This PDF file contains the front matter associated with SPIE Proceedings Volume 12261 including the Title Page, Copyright information, and Table of Contents.

This paper conducts research on the fuel consumption test method of heavy-duty commercial vehicles in China. The research firstly sorted out the fuel consumption standards and regulations of heavy-duty commercial vehicles in major countries in the world, compared and analyzed the advantages and disadvantages of various test methods, and proposed the overall test scheme including chassis dynamometer test and Simulation modeling. Based on the China cycles, this paper proposed the driving cycle, test conditions and test procedures for the fuel consumption test of heavy-duty commercial vehicles, and compared and analyzed the fuel consumption test results of typical vehicle models under two methods.

In response to the request of the client, we conduct on-site technical inspection of "China Fishery Administration 36236", then identify the consistency of its design drawings and ship construction drawings. At last, we analyze the reasons why the ship cannot maintain upright float, and on this basis A rectification plan is proposed to adjust the weight center of the ship, so that the ship has better buoyancy and stability performance.

The rotary-steering downhole closed-loop control has achieved drilling tool face regulation and control; however, the drilling distance is controlled via a command from the surface. Downhole ranging can compensate for the lack of surface control and is needed to achieve the global closed-loop control downhole. In this study, based on the basic theory of dynamics, a theoretical model of the well bottom, drill bit and -string dynamic system in guided drilling is built to simulate and analyze the regional distribution characteristics and influencing factors of drill string vibration during guided drilling. The study shows that with the increase in bit pressure, axial and lateral vibration intensities of the drill string transfer from the bottom to the wellhead and gradually weakens. The vibration stabilizes at a position higher than the neutral position of the drill string, and the comparison shows that the axial vibration intensity transfers more to the wellhead than lateral vibration under bit pressure; with the increase in rotational speed, the trend of transferring axial and lateral vibration intensities of the drill string, from the bottom to the wellhead, is similar to that under bit pressure; however, the transfer of axial and lateral vibration intensities to the wellhead is not evident with the increase in rotational speed. The study concludes that the optimal placement area of the rotary-steering downhole-ranging tool is the stable vibration region ranging from the well bottom to more than two times the distance between the neutral point and well bottom. This study can provide a reference for the study of downhole global closed-loop control.

Aiming at the problem of uneven fluid distribution in the working area of the mechanical ventilation system, a conceptual design solution process model based on the functional decomposition tree is proposed in this paper. After solving the model, three groups of structural optimization and improvement design schemes are obtained from adjusting the position of the pressure relief outlet and optimizing the parameters of the air distribution manifold inlet. The wind speed data of 180 monitoring points from 12 fluid characteristics simulation results are numerically calculated by 5 evaluation indexes such as wind speed difference at monitoring points and velocity uneven coefficient M. After four rounds of comparative analysis, the optimal scheme 3-3 is carried out. Comparing the results of original problem with Scheme 3-3, it is found that the difference of wind speed decreases from 0.915 to −0.009, and the velocity uneven coefficient M decreases by 18.44 %. It is determined that when the number of manifold outlets is 3 and the aperture a=0.05m, the effect on improving the airflow distribution uniformity in the working area of the mechanical ventilation system is obvious. The experimental results show that it is feasible and effective to apply the conceptual design solution process model based on the functional decomposition tree to the structural optimization design of the manifold for the mechanical ventilation system. The model can provide the theoretical basis for the optimization of the geometric parameters and structural improvement design of the mechanical ventilation system in many fields such as marine engine room ventilation systems and wood drying ventilation systems.

Taking a double ferrule pipe joint as research object, a nonlinear static finite element analysis model of double ferrule pipe joint is established by considering the elastic-plastic deformation characteristics of ferrule material and the contact nonlinear factors between different components. In Abaqus the contact pressure of the front ferrule body, rear ferrule front ferrule and rear ferrule pipe contact surface is calculated to evaluate the sealing effect of the double ferrule pipe joint. At the same time, the relationship between the cone angle of the contact slope of the rear ferrule and the sealing characteristics of the pipe joint is discussed. The simulation analysis and evaluation process of the double ferrule pipe joint considering nonlinear factors can provide technical guidance and optimization analysis for the design of ferrule seal.

This paper proposes an improved line-of-sight (LOS) guidance law for path following of Unmanned Surface Vehicle (USV) based on adaptive lookahead distance. The adaptive lookahead distance guidance algorithm of path following is designed as a new function of the USV’s cross tracking error to adjust the lookahead distance with less parameters and less initial lookahead distance, so that the USV reach the desired path quickly and stably in both straight-line and curve guidance. In the experiment, it is compared with other algorithms using the PID controller and Qihang USV model. The simulation results show the effectiveness of the adaptive lookahead distance algorithm in both straight-line and curve desired path. Compared with other guidance algorithms, the improved adaptive LOS guidance algorithm reaches the desired path faster for the first time and is closer to the desired path after stabilization.

Subglacial explosion is mainly used for ice breaking operation, and it is widely used in daily production and life, military, scientific research and other fields. When using numerical analysis software to deal with the ice breaking problem of nearfield underwater explosion, this paper takes the damage of shock wave load and bubble jet load to the ice layer as the research object. Aiming at the meso damage of ice layer under near-field underwater explosion, a numerical model of shock wave ice layer and bubble ice layer coupling effect is established based on one-dimensional stress wave propagation theory, The meso evolution process of ice damage under near-field underwater explosion is analyzed. Compared with the empirical formula and numerical calculation results, the law and mechanism of ice damage and crack propagation under near-field underwater explosions are obtained.

Designating special areas can reduce pollution caused by ships via adopting special compulsory methods. This paper quantitatively analyzes the types and feasibility of designating special areas in China. Firstly, the paper embeds the category, location, and direction of ocean currents of the functional area in specific sea areas by using Geo-Graphic Information System (GIS) to simulate the types of coastal sea area in China efficiently. Secondly, the fishing net data of 1km*1km in China sea area is established, and the ship point information in specific sea area is extracted by Automatic Identification System (AIS), and the ship density map is formed after the hierarchical rendering of fishing nets. Finally, classification rendering and transparent rendering are carried out on the vectorized spatial data and ship density of simulation respectively, to get the ship aggregation map of the functional area of the researched sea areas. By studying the characteristics of ship aggregation maps in various sea areas and combining with the international experience and methods of designating emission control areas, this paper puts forward a scheme of designating special areas in the Bohai Sea and its offshore waters, southeast coastal waters, and Guangxi Beibu Gulf waters, which has important reference value for China to apply for designating special areas in the future.

In order to quickly locate the damaged areas of submarine coating without entering the dock. The submarine surface corrosion current is equivalent to a series of point-type current sources, and the submarine underwater corrosion electric field is modeled. Based on Tikhonov regularization, the current intensity of the equivalent point-type current sources is inversed by the measured value of underwater electric field, and the damaged areas of submarine coating are located according to the corrosion current distribution on submarine surface. The validity of the proposed method has been proved through the comparison of the predicted and the practically damaged areas for a test submarine model.

Vessel head is an important part of the pressure parts in special equipment and its quality directly determines whether the pressure vessel can be reliably used. In this paper, the process of the standard elliptical vessel head is based on the metal shaping theory. Firstly, the process of EHA (based on the inner diameter) head is analyzed, the shaping of programs, drawing processes and tooling parameters are determined. Secondly, the finite element numerical method is used to simulate the process of stamping sheet to gain a comprehensive understanding of sheet metal forming. The forming quality is analyzed and evaluated by forming limit diagram, cloud thickness variation and spring back deformation maps. By changing the parameters of three stamping process, the impacts on shaping the results are discussed. The best molding solution is determined, which provides theoretical support for practical processing.

The ambient random vibration is one of the important factors affecting the flight safety and reliability of quadrotor unmanned aerial vehicles (UAVs). Therefore the vibration stress analysis of quadrotor UAVs with general structures is helpful to the structural design and optimization. According to vonMises Criterion, the stress analysis of main composite/metal mixed structures was carried out and according to Tsai-Wu Criterion, failure analysis of main composite structures was conducted. The numerical simulation results show that the main structures of the fuselage can meet the strength requirement; the arm is made of composite material by one-piece forming process, and the stress level of the arm pole is higher than that of the motor base; there is failure of composite material only near the hole of the arm riveted to the embracing ring. By optimizing the layering of the arm, it can reach the strength target of no arm failure under ambient random vibration with the weight reduced by 4.5%.

When the involute spur gear is working, a large bending stress is generated at the root of the tooth, which is prone to root fracture. In this paper, the double arc transition curve, the arc transition curve and the elliptical arc transition curve are compared. Through the dynamic finite element simulation of Abaqus software, it is concluded that the stress on the elliptical arc transition curve is the smallest. The stress at the root of the tooth can be reduced, the possibility of gear fatigue fracture can be decreased, which providing a certain reference for the design of plastics gears.

Spiral groove mechanical seal is one of the most favorite method when considering the extreme conditions in terms of the high speed, high temperature and high pressure in the industry. In this paper, the distribution of the temperature field and deformation of the friction pair interface of the spiral groove mechanical seal was studied based on the numerical simulation method. The results showed that the deformation of the sealing ring was relatively large with respect to the film thickness. On the other hand, the maximum deformation of the primary ring and mating ring was less affected by the speed, but the influence of the different pressure was relatively large. Therefore, the pressure of the mechanical seal needed to be controlled in production.

At the present stage, informatization and modern technology play an important role in promoting social development, which is a major development feature under the background of the new era. This paper studies the application of numerical control machining technology in machining and manufacturing, analyzes the characteristics of contemporary industrial production, summarizes relevant work experience, and points out the main problems existing in traditional machining operations. In this paper, the advantages of mechanical processing manufacturing are used as the main argument. It puts forward to meet the production demand for the purpose of numerical control processing technology functional advantages, hoping to provide scientific development suggestions for the industry workers.

Multi-axle heavy-duty special vehicles have the characteristics of large load and highe center of mass, which result the possibility of steering instability under high maneuvering conditions. The sideslip angle and yaw rate are the key criteria for measuring vehicle handling stability. If it is measured directly by on-board sensors, there are problems such as difficult measurement, high cost and long-term error. Therefore, the research on the state estimation of five-axle heavyduty vehicles is carried out. Firstly, based on the nonlinear three-degree-of-freedom vehicle model, a multi-axis heavyduty vehicle state observer based on Extended Kalman Filter is established to predict and estimate the yaw rate, sideslip angle and longitudinal speed of the vehicle. Then, a 13-degree-of-freedom dynamic model of a five-axle special vehicle is built based on Matlab/Simulink, and the driving state monitoring system is used to conduct real vehicle experiments to verify the accuracy of the model, which provides a theoretical basis for estimating the model and a verification simulation platform. Finally, the 13-degree-of-freedom model is used as the simulation platform to verify the fishhook condition, the double-line moving condition and the sinusoidal input condition. The research results show that the state estimator based on the nonlinear three-degree-of-freedom vehicle model can realize the dynamic estimation of the parameters of longitudinal velocity, yaw rate and sideslip angle.

Flow field structure of bipolar plate is an important factor affecting the electrochemical characteristic, pressure drop and water distribution of proton exchange membrane fuel cell. However, the power loss of exchange membrane fuel cell is large due to pressure loss along the way and local pressure loss in the traditional flow field (parallel, serpentine and spiral flow field). We designed a radial spiral groove flow field to reduce the pressure loss and improve the power of proton exchange membrane fuel cell. The performances of the designed radial spiral groove flow field and the traditional flow field in terms of electrochemical performance, cathode water concentration distribution and pressure drop were compared by numerical simulation. The results show that the radial spiral groove flow field can maintain the electrochemical performance as the parallel flow field, reduce the average water concentration and the key is to minimize the pressure drop in the flow channel, so as to ensure that the proton exchange membrane fuel cell has good drainage capacity, and reduce the pumping loss.

This paper studies the surface machining path representation based on NURBS and its key technologies of path planning, analyzes the advantages and disadvantages of various path planning algorithms for NURBS surfaces, and finds that the current NURBS surface machining path planning algorithms mainly consider geometric constraints, while There is less correlation analysis on the index of machined surface roughness, so it is necessary to combine intelligent algorithms and other technologies in the future to better solve practical engineering problems. Path planning algorithms are evaluated.

The time domain model of E-class road surface, the mathematical model of hydro-pneumatic suspension stiffness and damping, and the semi-vehicle model of 4×4 wheeled off-road vehicle are established. For military wheeled off-road vehicles, the evaluation method of ride comfort is put forward. Through MATLAB/SIMULINK programming calculation, the ride comfort of the vehicle is analyzed and the damping scheme is optimized. The ride comfort of the optimized vehicles is improved obviously through calculation.

Ships are high-consumption means of transportation. As a large energy consumer, the fuel cost is extremely high. Therefore, the fuel consumption can be reduced by optimizing the form of propellers. For traditional propellers, the shafting is one of the main sources of ship vibration, and the transmission structure is complex and the cost is high. Therefore, starting from the form of a shaftless propeller, the author cancels the transmission structure such as the shafting, adopts the electromagnetic drive propeller, and introduces The magnetic levitation technology avoids the problems of friction, vibration and noise when the propeller is running. At the same time, the method of fully enclosed fairing is adopted, so that the design has good sealing performance. The maglev propeller is more suitable for ships with all-electric propulsion systems, with no risk of oil leakage and no harmful gas emissions. It is very suitable for small and medium-sized ships.

Wave type defects can cause strip edge cracks and belt breaking accidents in the cold rolling process. Most of the researches only focused on the crack propagation in good plate shape, and there is still a lack of systematic research on the generation and expansion of cracks in cold-rolled strip with wave type defects. In this study, the uniaxial tensile constitutive relationship of the test material was obtained by tensile test combined with finite element simulation firstly. The neck shrinkage and fracture of the material were determined by metallographic test and scanning electron microscopy to determine the magnitude range of the volume fraction of some voids in the GTN model. Then the characteristic damage parameters in the GTN model were determined based on the GTN damage model combined with the response surface method; finally, the cold continuous rolling model was established by ABAQUS, and the influence of different wave type defects parameters on crack propagation was analyzed based on the GTN model. The results show that the length of crack propagation increases with the increase of wave height, decreases with the increase of wave length. The length of edge notch increases with the increase of wave height and decreases with the increase of wave width. The change in the length of the wave has little effect on the opening length of the notch.

Pressure relief valves of pressurized equipment as an important physical barrier, play a crucial role to protect pressure equipment, its reliability of performance and operation is directly related to the safety of the plants and personnel. From the point of view of Chinese laws and regulations, it is generally required that the in-service pressure relief valve would be calibrated at least once a year. However, that is in conflict with the demand of large petrochemical plants to gradually implement the 5 to 8 years long period operation. Based on risk assessment technology, the failure mode of the pressure relief valve was analysed, and the probability of failure and the consequence of failure for the pressure relief valve were calculated by use of quantitative RBI method. The criterion was proposed to determine risk-based calibration cycle of the pressure relief valve. Through the reasonable application of risk assessment technology for the pressure relief valve, it could meet the long period operation of the petrochemical plants under the condition of ensuring the normal operation of these valves.

Due to lack of recognized conclusions on the collision of truss jack-up offshore platform, when designers and inspectors study the collision performance of the jack-up offshore platform, they always rely on experience to select the simplification method of pile leg boundary conditions and various parameters required. The actual available equivalent boundary conditions of pile legs are not determined. To solve this problem, this paper selects the truss pile leg jack-up platform as the target platform for research. And modified the D-P constitutive model to established the "pile-soil" coupling model. At the same time, use the equivalent pile principle to established model. The finite element software ABAQUS is used for comparative analysis to determine the simplified boundary conditions which can be used for collision simulation analysis. The results can provide a reference for calculating the collision performance of truss jack-up offshore platform.

In order to solve the problems of manual traction, slow clamping speed and low efficiency of traditional clamper, a clamping scheme suitable for rapid clamping of rocket ammunition box was proposed. Through actions of components, the clamper can clamp and release the rocket ammunition box without appropriative power device and manual traction. The hoisting dynamics simulation under horizontal and inclined conditions was carried out using multi-body dynamics analysis software. In addition, the parametric model for the clamper was established to optimized mechanism size. The overall size was reduced by 10%. The results show that the clamper can be used for rocket launcher loading.

The main research work of this paper is: based on a 6-DOF industrial robot model, the finite element software ABAQUS is used to analyze the statics and modal characteristics of the model. Static analysis gives the stress, strain and deformation distribution. Based on the simulation results, the dangerous stress point are found, which provide an effective reference for the design and optimization of industrial robot.

Aiming at the problem that the risk assessment of mechanical product design stage the change of the state of man, machine and environment were ignored in use stage, a mechanical safety risk early warning method oriented to machine use stage is proposed. Firstly, the concept of mechanical safety risk warning is defined. Secondly, it provides the general process of mechanical safety risk warning, including the determination of monitoring elements, the determination of risk value calculation model, the determination of early warning level, etc. Finally, an industrial robot risk warning system is taken as an example to carry out risk warning experiment. The experimental results show that the mechanical safety risk warning can take the changes of the state of people, machines and environment into account, and take early warning measures according to the level according to the real-time monitoring information and online quantitative evaluation, so as to reduce the risk and improve the working efficiency of machines. It provides a new method for the security design of machine - oriented phase.

Wall climbing robots have a wide range of uses in civil, military and aerospace applications, yet there has been little research on the joint kinematic simulation of quadrupedal wall climbing robots. Combining the computational power of MATLAB with the mechanical simulation capabilities of Adams enables the joint kinematic simulation of a quadrupedal wall crawler robot. The quadrupedal wall climbing robot can achieve a sinusoidal smoothly varying diagonal gait.

Based on the calibration principle of multi-dimensional force sensor, the multi-dimensional force in-situ calibration method of space docking mechanism buffering test-bed is studied. A multi-dimensional force in-situ calibration device based on the standard force machine of worm gear structure and the calibration tooling matched with the special structure of the test-bed is established. The calibration tooling of the device is statically analysed by Mechanica software, and then the measurement uncertainty of the calibration device is analysed. Finally, the calibration device is verified by test. The results show that the calibration device can solve the problem of multi-dimensional force calibration of docking mechanism buffering test-bed.

More than half of the cooling load of the cold storage is caused by air infiltration at the door of the cold storage. In order to minimize the air penetration at the cold storage door, the air penetration during the opening and closing process of different types of cold storage doors is studied. The study found that compared with side sliding doors, the vertical lift door has a smaller hot air area in the cold storage during the door opening process. The vertical lift door is beneficial to reduce the amount of air infiltration during the door opening and closing process.

In order to solve the influence of condensation and frosting of traditional top row pipes on the goods in the cold storage, the indirect cooling refrigeration system with small heat exchange temperature differences in the local top row pipes is studied. The influence of cargo on the airflow organization in the cold room are studied. In view of the natural convection and radiation heat transfer process of the top row tube, FLUENT is used for numerical solution. The conclusion is as follows: When the cold storage is full, the average temperature in the height direction of the cargo area increases first and then decreases. When Z=0.9 m, the temperature field is the most uniform. Because the upper cargo is close to the pipe, the temperature inhomogeneity coefficient of the space Z=1.5 m and above increases significantly. There should be a distance of about 0.3 m between the cargo and the enclosure structure. When placing the goods, we need to avoid the space directly below the pipes as much as possible. There is a certain interval between the bottom of the goods and the goods. This can enhance air circulation and facilitate heat insulation and heat dissipation.

Central air conditioning is an important part of public buildings, but also one of the main energy consumption equipment. Air conditioning energy consumption generally accounts for more than 40% of the overall building energy consumption. Energy saving transformation of central air conditioning in public buildings is imminent and has great potential. This paper expounds the working principle of central air conditioning water system and process, analyses the advantages and disadvantages of different control methods of chilled water system and cooling water system, summarizes the six problems of central air conditioning operation, and analyses the energy consumption sources of the central air-conditioning system, and finally puts forward the improvement measures of energy saving in the operation of the air-conditioning water system. It provides reference for energy saving transformation of central air conditioning system.

Based on CFD, a comparative analysis of the lift coefficient, drag coefficient, and lift-to-drag ratio of NACA4412 hydrofoil under different influencing factors was carried out. The results show that when the cavitation number is small, the lift and drag coefficient increase monotonically with the angle of attack, while the lift-to-drag ratio decreases monotonically with the angle of attack; both the lift coefficient and lift-to-drag ratio increase monotonically with the cavitation number, and the drag coefficient first increases and then decreases with the decrease of cavitation number; both the lift coefficient and lift-to-drag ratio decreases monotonically with Reynolds number, while the drag coefficient decreases monotonically with Reynolds number as a whole; on the premise of constant Reynolds number, the size has a greater influence on the lift and drag coefficient and a smaller influence on the lift-drag ratio.

With the introduction of the dual-carbon goal, the role of transportation electrification in carbon reduction has been paid more and more attention, and the electrification of ports and ships is also an indispensable part of it. However, the current Vessel-Grid-interaction (VGI) operation model is still unclear. This article proposes a method of power grid interaction value analysis for ship-based charging stations in response to this situation, in order to provide a path for future research of V2G (Vessel-To-Grid). From the perspective of the value of the whole society, this article comprehensively analyzes the economic effects of vessels charging stations participating in multiple grid interactive services. The limit method and the curve method are respectively proposed to evaluate the elasticity of ships. Comprehensive consideration of orderly charging (represented by V1G) and V2G scenarios brings many benefits, such as reducing peak power plant investment, improving local distribution network power supply capacity, improving distribution network line reliability, reducing power outage losses, and absorbing local new energy. The results show that the scale effect in the VGI scenario does not become more and more obvious with the increase in the number of vessels. On the one hand, the demand on the grid side will reach saturation at a certain point, and on the other hand, the investment and operation and maintenance costs will also be greater. We can stimulate more vessels to participate in VGI through some means, but at a certain point, the optimal balance point will be reached, and then more stimulation will be very uneconomical;

Oil spills seriously threaten the safety of the marine ecological environment, in coastal cities. Small-scale oil spills along the coast occur more frequently. Although the spill is small, attention should be paid. Emergency equipment stations should be set up along the coast to store emergency supplies such as oil skimmers. For small-scale oil spills along the coast, in order to determine the optimal configuration plan for the number of oil skimmers in emergency stations, we use a multiobjective particle swarm algorithm to construct a configuration model, and comprehensively consider the impact of oil spills on the environment and the depreciation cost of oil skimmers. A decision plan for the number of oil skimmers used in the small-scale oil spill emergency station for regional control is given. Taking a peninsula sea area as an example to analyse the application of the model, and the optimal decision of the number of oil skimmers in the emergency station in the sea area is given. The research results can provide reference for coastal city planning.

With the development of new technologies and the rise of 5G in China, top-level design has accelerated the new generation of infrastructure construction. 3D printing is a manufacturing technology with pronounced digital characteristics, and 3D printing has irreplaceable benefits compared with the traditional manufacturing industry. The technical principle of the 3D printing technology could be using adhesive materials, including powdery metal and plastic, to construct the object layer by layer based on the digital model files. This paper will introduce 3D printing technology in detail, including the process of 3D printing from the perspective of software application and several standard 3D printing technologies at present. This paper will also discuss both the application and the development of three-dimensional printing technology.

In order to study the effect of different altitudes on vehicle emissions, two China Ⅵ light-duty gasoline and diesel vehicles are selected to carry out pollution emission tests at different altitudes in the altitude environment simulation chamber. The result show that with the increase of altitude, CO, HC and PM emissions show an upward trend, and NOx emissions show a fluctuating downward trend.

The technologies of ballistic missile and ballistic missile defense system have become the focus of mutual strategic balance and competing development among the major powers since World War II. Russia has inherited the ballistic missile and defense technology left over from the former Soviet Union during the Cold War and has carried out a lot of innovation and development on the existing basis. Russian ballistic missiles focus on the trinity development strategy of sea, land and air, and gradually change the original strategic goal of focusing on land but supplementing by sea and air. The Russian ballistic missile defense system continues to use the former Soviet Union's plan and has the main purpose of defending the important goal of the homeland. This article focuses on the development history and development status of Russian ballistic missiles and ballistic missile defense systems, and forecasts and analyzes the future development trend of Russian ballistic missiles and anti-missile systems.

The research used organometallic ultrafiltration membranes to treat wastewater containing aviation kerosene. After a long operation test, the effect of operation time on water production per unit membrane area was investigated. The research showed that the water yield did not fluctuate significantly during the 90 min of operation. The effect of differential pressure across the membrane on the performance of recovery rate, membrane flux and oil removal rate was investigated by varying the feed water pressure. The research showed that when the operating pressure was increased from 0.14 MPa to 0.2 MPa, the produced water flux increased from about 43 L/h/m2 to about 66 L/h/m2, the single-stage recovery rate increased from 20% to about 40%, and the oil removal rate decreased slightly but was still higher than 90%. The effect of changing the initial oil-bearing wastewater concentration on the oil removal effect was investigated. The research showed that the initial oil concentration was higher than 90% in the range of 30mg/L-100mg/L.

The inspection of gas generators is dangerous. This paper identifies and analyzes the hazard sources in the gas generator inspection process, and puts forward the corresponding hazard source safety protection strategies on this basis. The hazards in the gas-steam launch power system inspection can be summarized as man-made hazards, the inherent hazards of the test object, and the hazards caused by the environment and other factors. The hazards of human factors can be protected by measures such as personnel training, strengthened supervision, dynamic management, and emergency response plans. The inherent hazards of the inspection object can be protected by measures such as safety status confirmation, equipment status confirmation, and the use of special tooling. The environment and other sources of hazards can be protected by measures such as improving the inspection environment, perfecting the environmental system, optimizing detection methods, strengthening personnel protection, and using advanced equipment.

The main hydraulic tank of the main hydraulic source of a certain type of aircraft is a closed self-supplied supercharged tank, which can not only increase the pressurized pressure of the tank, but also improve the stability of the system. This paper studies the abnormal heating of this kind of oil tank and the failure that the supercharged pressure of the fuel tank can not be maintained. Fault tree analysis method is used to analyze the fault phenomenon, and fault troubleshooting is carried out from both static and dynamic aspects. Finally, it is concluded that the cause of the abnormal heating of the main hydraulic tank is the fault of the safety valve of the main hydraulic tank.

Under the actual working conditions, the shaft system of micro gas turbine is often subjected to torsional load due to a variety of factors. As the key flexible part connecting multi span rotor on gas turbine, the torsional characteristics of closed interference fit diaphragm coupling have the most direct impact on the static and dynamic torsional performance of the system. Based on this problem, by simplifying the solution model of the diaphragm coupling, this paper studies the torsional characteristics of the diaphragm coupling by means of simulation analysis, gives the deformation and stress distribution on the diaphragm and intermediate shaft under torsional load, and solves the torsional stiffness of the diaphragm coupling, It lays a foundation for further study on the influence of coupling on the dynamic performance of shafting and optimal design.

In order to explore the ignition performance of ramjet combustor, based on the establishment of ramjet combustor model, the ignition process was numerically calculated by using numerical simulation method, and the flow field and flame development process in the combustor were analyzed. The results showed that a backflow zone could be formed behind the blunt body evaporative flame stabilizer in the ramjet combustion chamber. The air holes on the cyclone could lead to the separation of flame roots in the backflow zone, but did not affect the overall shape of the flame. After the igniter exits, the initial fire core expanded around and ignited the surrounding fuel mixture, making the temperature of the fire core drop from 2800K to 2000K; Compared with the normal ignition process, the increase of oxygen concentration could significantly increase the flame propagation velocity and flame temperature, and shorten the ignition delay time of the combustion chamber.

Green environmental protection was the development trend of my country's ports, and it was also the direction of the transformation and development of bulk cargo terminals. Based on the assessment and screening methods of dry bulk terminal pollution prevention technology, the analytic hierarchy process was used to comprehensively evaluate the potential dust pollution control technologies, and the best practice technology for dry bulk terminal dust pollution was screened out.

Aiming at the problems of untimely treatment and low efficiency of modern factory waste gas treatment methods, this paper innovatively combines microwave catalytic oxidation organic waste gas with microwave regeneration activated carbon, and designs an electromechanical integration device, which can effectively and quickly treat volatile industrial organic waste gas. Microwave has the advantages of strong selectivity, easy control, no secondary contaminants, n the process of catalytic oxidation, selective heating can improve the catalytic performance of the catalyst, prolong the service life of the catalyst, and purify the sulfur-containing nitrogen oxides and volatile organic compounds in the air more effectively, which is of great significance to improve the atmospheric environment.

The use safety of elevator is related to daily life. The landing door of elevator is the most direct protective barrier for users. In the process of elevator use, the landing door is a mechanism with high use frequency. However, due to maintenance, use, management and other reasons, accidents caused by landing doors occur from time to time. Therefore, the safety of elevator landing doors should be paid enough attention by relevant personnel. At present, a variety of tools are needed to detect the deformation of landing doors, and it is not convenient to detect elevator landing doors with different widths, resulting in low detection accuracy. This paper studies a device, which can reduce the types of tools needed to detect the deformation of landing doors, and improve the accuracy of detecting elevator landing doors with different widths.

Aiming at the complicated serial and parallel relationships of tasks in ship collaborative design and manufacturing, this paper first establishes a planning model for minimizing design time, and proposes a time-efficiency-relevance priority traversal task scheduling strategy (DERP). Second, it proposes the improved immune genetic algorithm solves the problem of task scheduling, reduces design man-hours, improves the efficiency of ship collaborative design and manufacturing, and reduces design costs. Finally, the effectiveness of the algorithm in this paper is verified by simulations on different scale ship design tasks. The results show that the improved algorithm can solve the design task scheduling problem very well.

The purpose of this paper is to investigate the influence mechanism of heave damping on the energy extraction of a fully passive oscillating hydrofoil in a turbulent environment. The effects of heave damping on the performance parameters and the shedding process of the leading-edge vorticity are studied. The results show that increasing heave damping will change the synchronization of heave motion and pitch motion, and then affect the formation and shedding process of the leading-edge vorticity. This leads to a reduction in the force and speed of the hydrofoil, and the final captured energy will decrease accordingly. In addition, some damping in heave is required by the fully passive oscillating hydrofoil to stabilize the amplitude of motion, thus avoiding excessive amplitude that may damage the structural integrity of the equipment.

The vibration and noise caused by shock in the working state of the marine gearbox seriously affect its performance. It is of great significance to analyze the vibration characteristics of the gearbox and then reduce its vibration and noise level. In this paper, a spring vibration damper is added to the gearbox and the finite element method is used to analyze the dynamics of the gearbox to obtain the vibration characteristics of the gearbox. The radiation noise characteristics of the gearbox are obtained by the direct boundary element method and then use the sound pressure distribution of the external acoustic field to optimize the noise of the gearbox. The results show that after adding a spring radiation damper to the bottom of the gearbox, the noise radiation power is reduced by more than 10%, which can effectively reduce the vibration and noise.

Titanium alloy possess outstanding comprehensive properties, and they are important metal structural materials which have been widely used in aerospace industry, chemical industry, marine engineering and other fields. TC4 alloy was formed by selective laser melting (SLM) technology. The effects of laser power and scanning speed on the mechanical properties and microstructure of the alloys were analyzed by tensile testing machine and metallographic microscope. The results showed that the change of scanning speed and laser power showed significant effects on the mechanical properties and microstructure of the TC4 alloy by SLM. The optimal laser power and scanning speed of TC4 alloy formed by SLM are 300 W and 1.5 m/s, respectively. Under these conditions, the tensile strength and elongation of the alloy are 1282.23 MPa and 8.89%, respectively.

Oil boom is an effective containment facility to reduce the damage of oil spills. In this paper, a new manoeuvrable boom deployment device is proposed for oil spills at sea. The device adopts a 2.4GHz wireless remote control model control system , which can remotely deploy or retrieve the inflatable boom by carrying a roller type boom deployment and recovery device. The device has the advantages of remote control, ease of use, rapid deployment and low cost, which can effectively reduce the risk of personnel during the deployment of the boom on site.

In the use of a new type of ignition device for a solid rocket motor, its case is required to have high tensile strength. The finite element software is used to simulate the structure of the ignition device, and the bearing capacity of the ignition device is evaluated and analyzed by simulating the axial tensile test loading of the ignition device. In extreme situation, there is a possibility of partial structural damage to the ignition device. According to the analysis results, the wall thickness of the device model is increased, and the revised ignition device has passed the simulation analysis and test verification. The verification results show that the tensile structural strength performance of the new ignition device meets the design requirements, and the structural strength simulation calculation method is accurate and effective, close to the experimental test. The results are of guiding significance for the design, optimization and test of the ignition device with high tensile structural strength of solid rocket engine and its similar structures.

High-pressure heaters, as an important auxiliary machine to improve thermal economy, are an important part of a million-level secondary reheat unit. With the continuous deepening of the supply-side reform and the development of high-end power equipment for higher parameters, the serpentine tube heaters will become the mainstream of future development. The pipe bend wall thickness designed by GBT 151 is higher than that of foreign products, and there is a certain gap in economic and energy efficiency compared with foreign products. Through the finite element analysis, it is found that the serpentine tube could be designed according to the EN 12952-3 standard under the premise that the bending process meets the thickness of the inner and outer walls.

At present, the main problem of the residual film recycling machine is the difficulty of membrane soil separation, resulting in high soil content after residual film recycling, and the soil is easy to adhere to the working parts during the recycling process, resulting in high film wrapping rate. To solve this problem, two types of membrane soil separation devices, pneumatic and rotary vibration, and two types of membrane soil separation devices, are designed. This study provides a basis for the design and optimization of membrane soil separation devices in the follow-up.

This paper researched on how to realize a given trajectory more accurately by designing a planar four-bar linkage. In order to reproducing a given curve accurately, analytical synthesis and optimal algorithm were used in this paper. Mathematical model was established at first, the dimension of each link, location of the fixed hinge center and some angles between the links were taken as design variables. Then the objective function is established by calculating the root mean square error between the coupler curve and the given curve at the specified N points. According to Grashof Criteria and the minimum value of the transmission angle, the constraints of the design were determined. The iterative method is used to find the optimal solution of the objective function. Thirdly, an optimal design program were written through the use of Matlab Software to achieve the method. Finally, an example is given to verify the feasibility of the optimization program.

In this paper, the deployment mechanism of the spaceborne umbrella deployable antenna is taken as the research object. The working principle of the deployment mechanism is introduced, and the equation of motion of the deployment mechanism is obtained by using the analytical method. Combined with the structural parameters of the moving parts of the antenna deployment mechanism, the motion law of the key parts of the deployment mechanism in the process of antenna deployment is obtained. Through the force analysis of the deployment mechanism, the structure optimization model of the deployment mechanism is established, which takes the structural parameters of the deployment mechanism as the design variables and the minimum driving force as the objective. Through the ergodic method, the optimized structural parameters of the deployment mechanism are obtained. The maximum driving force of the optimized deployment mechanism is 30% lower than that before optimization, and the optimization effect is remarkable.

A deformation-enhanced particle swarm optimization (DEPSO) is proposed for performance-based design optimization (PBDO) of steel braced frames. The deformation information of structural elements is a sign of material efficiency, but in particle swarm optimization (PSO), such information is directly discarded. In the proposed DEPSO the deformation information is conditionally added to the optimization process of PSO, thus an enhanced searching ability can be achieved. One numerical example is solved using DEPSO and PSO, in which the structural weight is minimized while satisfying given performance requirements. The results demonstrate that DEPSO is capable of finding lighter structural designs than PSO with less computational time.

In order to solve the problem of circulation hole blockage for pressure opening blast device after perforation in ultra-deep and ultra-high pressure well, and reduce the operation risk, a new type of anti-blocking ultra-high pressure opening hole blast device is developed for detonate the perforating gun. In ultra-deep and ultra-high pressure well, this device along with perforation gun is delivered to work through tubing transmission. During the design, the structure of the device is optimized, and the whole mechanical strength of the device under tensile loads is discussed using finite element analysis method. Meanwhile, the reliability of the device is verified through the ground test. The field experiment indicates that the anti-blocking pressure opening hole detonator is feasible and effective. The effect of normal detonating, normal opening hole and normal circulation can be successfully realized. The new detonator is recommended to promote the applications for tubing conveyed perforating (TCP) completion in the domestic fields. The anti-blocking pressure opening hole blast device has important practical significance for shortening the perforation duration and reduce the operation cost in TCP operations.

This paper researched on how to realize a given trajectory more accurately by designing a planar four-bar linkage. In order to reproducing a given curve accurately, analytical synthesis and optimal algorithm were used in this paper. Mathematical model was established at first, the dimension of each link, location of the fixed hinge center and some angles between the links were taken as design variables. Then the objective function is established by calculating the root mean square error between the coupler curve and the given curve at the specified N points. According to Grashof Criteria and the minimum value of the transmission angle, the constraints of the design were determined. The iterative method is used to find the optimal solution of the objective function. Thirdly, an optimal design program were written through the use of Matlab Software to achieve the method. Finally, an example is given to verify the feasibility of the optimization program.

The use environment of rubber shock absorber is changeable. The degree of maintaining stable working performance in different environments is an important reference factor for selecting shock absorber. Based on the temperature condition, this paper studies the damping effect of the same type of shock absorber on the same load at different temperatures. Keep the shock absorber at a certain temperature through the temperature box, and then conduct vibration test on the load to test the performance of the shock absorber. The results show that in the range of - 50 ~ 65 ℃, the performance of the shock absorber at low or high temperature changes little compared with that at normal temperature, which will not affect the shock absorption effect of the shock absorber at all.

This paper proposes a multi-situational FBS and Quality Function Deployment (QFD) integrated product design requirements model for more accurate product positioning, longer product life and improved product design rationality.A multi-situational FBS-QFD model is constructed to design products by analysing the relationship between the needs of realistic and ambiguous user groups and product functionality.Specific steps: clarify the design objectives, analyse the scenario-structure units of the design objectives, and analyse the mapping relationship between scenario-functionbehaviour- structure after building the FBS model.Predicting scenario feasibility, identifying user requirements and translating them into design features.Determine design feature scores and their positive and negative correlations, construct a matrix of user requirements and design feature relationships, derive key design innovation areas and functions, and complete product design solutions.The validation of the model is carried out using rehabilitation products as an example. The study shows that the model is scientific and can improve the quality of product design.Provides a theoretical basis and practical strategies for product design decisions.

The ultrasonic excitation system consists of ultrasonic excitation power supply and ultrasonic transducer. Ultrasonic transducer is an important part of ultrasonic scalpel excitation system. Its main function is to convert the alternating electric signal sent by ultrasonic excitation power supply into ultrasonic signal (ultrasonic vibration), so as to complete energy conversion. Due to the large amount of information, energy concentration and strong penetration, ultrasonic transducer has been widely used in production and life, and ultrasonic transducer has developed rapidly. This paper designs the structure of a sandwich piezoelectric ceramic transducer, analyzes the vibration mode of the amplitude transducer through the workbench finite element analysis software, analyzes the vibration characteristics of the transducer, and verifies the performance of the designed transducer.

On the basis of professional theories such as launch dynamics, ballistics, flight stability, vibration theory, multi-body system kinematics, aerodynamics, etc., this paper proposes a design method and system of a JDAM ballistic fast solver. The system includes JDAM ballistic calculation module, dispersion accuracy analysis module, data interaction interface and ballistic display module, etc., complete JDAM ballistic calculation and simulation, and realize the standardization, process and automation of ballistic calculation and simulation work.

Hydrogen energy as a renewable energy in the world today, plays an increasingly important role, in order to make full use of hydrogen energy, will be liquefied hydrogen storage and transportation is the only way. According to the standard GB150-2011"pressure vessel" , this paper calculates the structural strength of the 2-ton helium expansion refrigeration hydrogen liquefaction vacuum cold box, and uses ANSYS to carry on the finite element analysis to its normal operation and the sudden working condition(Pipeline leakage condition), the displacement nephogram and stress Nephogram of the cold box under two working conditions are obtained, and the structure of the cold box was modified reasonably.

Aiming at the contradiction between the need for the planetary rover wheeled mobile system to overcome obstacles in the complex and unstructured environment of planet surface and the limited spacecraft volume, this article proposes a new type of guide rod telescopic initiative variable spoke wheel based on the synthesis of multiple principles of variable spoke mechanism and cam transmission. The model of guide rod telescopic wheel is established, and the forming principle of the cam profile the core component to realize the initiative transformation of spoke is deeply studied. Taking the highest energy utilization efficiency, the smallest variable spoke driving torque, and the best stability of the variable spoke motion as the cam profile optimization goals, this article establishes a static and dynamic simulation model of initiative spoke transformation of variable spoke wheel. The kinematics and dynamics mechanism of different cam profile on the variable spoke wheel is analyzed in detail. The focus is on the dynamic influence of Archimedean spiral and logarithmic spiral cam profile on the performance of the initiative variable spoke mechanism. Theoretical analysis results and simulation analysis results both show that the peak torque of the Archimedean spiral cam profile is reduced by more than 56% compared with the logarithmic spiral, and the average torque is reduced by more than 30%, which means the weight and energy consumption of initiative variable spoke driving part are significantly reduced. The research results of this article will provide reference and theoretical basis for the design of variable spoke wheel and the analysis of related modules of variable spoke.

To address the low sorting efficiency of existing food vending machines, the single way of picking up food and the low success rate of picking up. By analysing the physical properties of typical foodstuffs in our canteens, the corresponding picking methods are proposed and statistically. Based on this, a structure with integrated end-effector is proposed to complete the design of the relevant mechanical structure of the food vending machine; the kinematic equations are established using the D-H method; the working space of the food vending machine is analysed in Matlab using the Monte Carlo method; the motion planning of the food vending machine is carried out and the kinematic simulation is performed by ADAMS software. The results show that the design dimensions and the kinematic planning are reasonable and meet the requirements for the working space and sorting operation of the food vending machine.

In order to improve the dynamic performance of deployable truss structure, a two-level optimization method for composite rods is proposed. The first level optimization takes the number of standard lay-ups as design variable, and the weighted sum of the fundamental frequencies of the truss structure in the folded and deployed states as the objective function. The simulated annealing and Bayesian regularization are employed to obtain the optimal standard spread layers of BP neural network, where the optimal number of standard lay-ups is obtained by the neural network mapping. Based on the results of the first level optimization, the second level optimization takes the orientation and thickness of each layup as the design variables, and a multi-objective optimization is formulated with the objective is to maximize the fundamental frequency and minimize the structural mass. The multi-objective optimization problem is solved by using the NSGA-II algorithm. The results demonstrate that the proposed method can effectively increase the fundamental frequency of the deployable truss structure in both the folded and deployed states, and at the same time realize the lightweight design.

Lightweight wall forming machine is the use of fly ash and other industrial waste for lightweight wall panel extrusion manufacturing of automated molding equipment, there are equipment automation, low degree of mechanization, product quality can not be controlled and other shortcomings. This paper completes the innovative design of the lightweight wall forming machine by establishing a three-dimensional model of the lightweight wall forming machine, performing motion analysis and force analysis of the spiral reamer of the equipment, and completing the control circuit design of the device, based on the mechanical analysis and finite element analysis of the spiral reamer and vibration cavity, the rationality of the innovative design structure of the lightweight wall forming machine is verified. The innovative design of the lightweight wall forming machine can achieve automatic production, high production efficiency, can achieve continuous board making, is conducive to improving the surface light sensitivity of the wall panel, increase production efficiency.

Surface Mount Devices (SMD) greatly improve the product integration and the chip package area ratio. On the other hand, due to the large number of pins and the very small volume of solder joints, it is easy to crack solder joints in the vibration environment of spacecraft launching, which causes the strength reliability problem. The bending stiffness of SMDs is compared with that of printed circuit boards (PCB) and is analyzed by using the bending stiffness theory of plate in this paper. The key factors, which affect the vibration reliability of SMD solder joints, are obtained. A PCB stiffening rib design method to improve the vibration reliability of SMD is given from the aspect of the structural system design of the electronic equipment. By using the finite element method (FEM), it is verified that this method can greatly reduce the relative displacement between SMDs and PCBs, and effectively improve the anti-vibration characteristics of SMD solder joints. The method also has the advantages of reducing the overall size of electronic equipment and facilitating the application of heat sink to the heating components, and has been widely used in various types of aerospace electronic equipment.

According to the requirements of bracket lightweight, high stiffness and on-orbit operation, the variable density method topological optimization theory is applied to the bracket optimization design. Firstly, the total flexibility of the bracket is the target function, and the material volume as the constraint function. A mathematical model applied to the target topology optimization calculation is established, and the optimization parameters are determined. Secondly, by analysing the various load working conditions of the bracket and analysing the optimization results of multi-load conditions together, the optimized design reduced the bracket quality by 51% from the initial model, the overall fundamental frequency of the bracket and connectors is 321Hz, which is higher than the index requirements. Through the simulation and verification, the bracket meets the strength requirements and verifies the rationality of the structure optimization design.

For the purpose of optimizing the artificial detrusor driver, the mechanical model and finite element model of the driver are established, analyzed and simulated. Taking the deformation displacement and mass as the optimization objectives, the response surface relationship between the design parameters and the optimization objectives is obtained from the simulation results. The micturition performance was simulated and experimentally studied by establishing an experimental platform. On the premise of ensuring good urination performance, the mass of the optimized SMA driver is reduced by 40% compared with that before optimization. The research of this paper proves that the optimization analysis model and simulation model are effective and practical, which provides a reference for the design of artificial detrusor system suitable for clinical research.

The high frequency transducer usually has a narrow working band which limits the underwater target detection performance of high-frequency sonar. Matching layer is an important technology to expand the working band. Due to the complex manufacturing process, previous researches are mainly based on simulation results. In this study, a series of transducer with matching layer were made, and the admittance were measured both in air and in water, The influences of matching layer thickness on the performance of transducer were obtained, which is useful for the optimal design of high frequency transducer. Under the optimal matching layer thickness, the bandwidth of the transducer exceeded 60kHz with the center frequency of 115kHz.

In this paper, the optimal design of the large spaceborne antenna supporting structure with load-bearing barrel-brackets configuration is studied. In this form of structure, the satellite and the antenna supporting structure are provided with a central load-bearing barrel, and the two are connected to each other as the main bearing structure; the antenna parts are connected to the load-bearing barrel through a series of brackets. A topology optimization design model of the antenna supporting structure of the load-bearing barrel-bracket configuration is constructed. The layout of the supporting brackets structure is ensured through methods such as design space segmentation and independent material volume control.

Taking a cruise thruster as the research object, the sound pressure distribution in the flow field of the thruster is obtained through CFD calculation and analysis. The calculation results show that the axial frequency energy is more sensitive to the incoming flow velocity. Due to the existence of the side thruster channel, the dynamic and static interference is formed between the propeller and the channel wall. The calculation results show that the closer to the leaf tip, the higher the energy of leaf frequency and its doubling. The research results can provide important reference data for the optimization design of thruster structure, and have certain engineering practical value.

Based on the agronomic characteristics of ridge planting raw sugarcane in tropical areas, this paper mainly designs and analyzes plough body parts for subsoilers. In order to verify the rationality of plow body design, this paper analyzes the plow body through SolidWorks Simulation, and obtains its stress distribution state under extreme conditions. The results show that the final optimized structural parameters are the thickness of the plow handle 28 mm and the angle of the end face of the plow is 15 °, which provides a reference for the optimization and improvement of the plow structure of sugarcane subsoiling machine.

Based on MBSE, a TSRFA method was proposed to solve the problem of multi-parameter coupling design. The method is divided into three parts: Digital model analysis, Virtual prototype model, and Physical prototype model. By integrating methods such as qualitative analysis, quantitative analysis and evaluation integration (QQE) to build a unified demand analysis with multiple parameters of coupled agronomy; by integrating industrial design ideas, using CAD modeling and CAE performance simulation. Finally, the feasibility of TSRFA method is verified with the subject case, and the design process is provided for the subsequent development of intelligent agricultural equipment.

Dynamic force calibration devices are measurement standards used to calibrate dynamic force measurement characteristics. The working process of a dynamic force calibration device is developed as a measurement process for the calibration of dynamic forces. On the basis of the study of dynamic force calibration devices, the specific calibration methods are introduced in this paper, and the current status of the research and development of dynamic force calibration devices is looked forward to, which has certain reference and guidance significance for further dynamic force calibration and traceability level.

The wallboard extrusion molding technology is oriented to sustainable development and is committed to green production. In order to meet the process requirements, the existing molding machine is optimized. Based on the working principle of the wallboard extrusion molding machine, improve the overall movement and lifting function, connect the screw feed rod with the bottom end of the hopper, improve the utilization rate of raw materials, and add a pressure sensitive sensor to control the supply of raw materials to avoid waste of raw materials. Through the action of gravity and inclined plane component, it is convenient for the equipment to discharge the plate, and the finite element analysis of the screw feed rod is carried out to verify the feasibility and effectiveness of the system, optimize the operation process of old-fashioned industrial production equipment, and realize automatic supply to a certain extent.

Typical spaceborne high-gain parabolic antenna generally has large diameters, due to the harsh on-orbit operating temperature environment, the on-orbit thermal deformation state of the antenna is complex. In order to ensure the stable performance of the high-gain parabolic antenna in orbit, the technical difficulties of antenna stability control in orbit were sorted out, simulation analysis and test verification were carried out, and the temperature field and thermal deformation distribution under different working conditions were simulated and analyzed. Based on the thermal deformation data, the in-orbit performance of the antenna in thermal deformation is evaluated and analyzed by semiphysical simulation analysis method. The results show that the performance changes caused by thermal deformation are all within the design margin.

In order to protect the safety of optoelectronic equipment during transportation, a vibration isolation system suitable for optoelectronic equipment transportation is designed and tested. Firstly, the passive damping theory is analyzed, and the vibration isolation system is designed based on this theory. Then the modal analysis of the vibration isolation support is carried out. Finally, the vibration test of the specific equipment is carried out. The results show that the overall damping effect of the damping system is remarkable and the stiffness of vibration isolation support directly affects the trend of the vibration transmissibility curve.

Pilot seat is one of the most important equipment in the cockpit of civil aircraft. This work mainly introduces the design and research of the pilot seat of civil aircraft. Firstly, it introduces the components of the pilot seat and design difficulties. Then it studies several key issues which need to be considered in the design of the pilot seat, especially the airworthiness and comfort requirements. In addition, some suggestions for seat design are also described in this work. This work offers great value for the design of pilot seat in civil aircraft.

Civil aircraft Extended Operations (ETOPS) type design[1] and approval is studied. Firstly, the basic concepts of ETOPS are briefly introduced. The airworthiness requirements and approval methods related to ETOPS type design are sorted out. Through the study of airworthiness requirements and relevant guidance materials, a design process of obtaining ETOPS type design approval by using service experience method is proposed. The engineering practice shows that the design process proposed can guide the ETOPS type design and certification of domestic civil aircraft.

Based on the V-hull theory, a 3500DWT oil tanker was used as the mother ship, which was transformed into a no-ballast water ship. Two key problems, the determination of the dip Angle and the transformation of the non-parallel middle body part, are solved in the transformation. The designed non-ballast water ship has the same displacement as the mother ship when it is full load, and does not need ballast water when it is empty, and its stability is better than that of the mother ship.

A wind power generation Co., Ltd. in Inner Mongolia. On a certain day in 2017, when eliminating the defects of a wind turbine, the operation inspection personnel found that a high-strength connecting bolt at the connection between the foundation ring of the wind turbine and the first cylinder section of the tower was broken and failed.

With the development of weapon designed to actual combat, when the launching platform is launching missiles at high speed or in formation cluster state, the debris of gas rudder thrown down during missile flight is easy to pose a threat to the moving platform or other platforms in formation, and there is a great security risk. In this paper, aiming at the safety requirements of the platform when the platform is launching missiles at high speed, the trajectory design method to improve the safety of the missile rudder remains is studied. This paper proposed the program angle configuration of "suppress first and then lift", and carried out the parameter optimization design and risk analysis, which effectively improves the safety of the rudder remains.

To achieve water abstraction irrigation from air and solve the problem of irrigation water source with less human resources, a new water-saving irrigation device based on heat convection inclusion tracts is designed. Methods: Operating on the refrigeration semiconductor and running on light energy generation, continuous water abstraction from air is accomplished. Designing a data collection and formating a delivery system, water-saving irrigation is intelligentized. Content: Innovativeness utilizing the refrigeration semiconductor and adiabatic partition enclosed into a condensation structure, so that the air evolves moisture from the air as it passes through the condensation structure, and at the same time, a gas channel is set at the bottom to facilitate the emission of cold air, using FLUENT software for three-dimensional numerical simulation analysis. Conclusion: The apparatus is remarkable for its simple structure installed and maintained easily, high efficiency and independence of environment-friendly water intake. At the same time, a data acquisition and transmission system is designed to enable each independent device in the area to be managed and maintained centrally. As well as the micro-adjustment of water use, it can play an important role in desert greening, road greening, lawns, gardensagricultural water-saving irrigation, and domestic water use.

In order to solve the problem of storing the bike properly, we design a kind of underground vertical bicycle storage device. It is mainly divided into the well part, the lifting part and the clamping part. The planar four-bar mechanism is optimized, so that the support plate can complete horizontality and verticality two kinds of working condition. The combination of hardware and software implements one location for a bicycle. It not only saves space, but reduces the possibility of bicycles being stolen. After the test, the total running time of the device is about 20s. It has the advantages of simple access, high efficiency, fast, small space, good stability and no jam.

The submersible transformer is one an essential part of Remote Operated Vehicle (ROV) which worked in Deep Ocean. The water pressure will beyond 30MPa under 3000 meter in ocean. Well sealed and perfect insulation is the necessary condition for the submersible transformer. The sealed performance is the key technical problem of the shell. Four kinds of sealed shell was studied in this paper, the bladder-type pressure compensation submersible transformer shell is ideal and suitable after theoretical calculation an experiment.

The overspeed protection device is a key device of the turbine to prevent turbine overspeed. Most domestic units use the double protection of electrical overspeed protection and mechanical overspeed protection in their design. Nowadays, with the application of digital control and protection system, electrical overspeed can achieve different degrees of "fault tolerance" through appropriate redundancy technology, which greatly improves the reliability of security system. However, due to the complexity of the structure and other reasons, mechanical overspeed protection has the situation of "mal-operation" or "refused operation of protection", and it can't achieve the "fault tolerance" of the system. On the basis of introducing the setting of overspeed protection device of some units at home and abroad, this paper analyses the shortcomings of the mechanical overspeed protection device of this unit, and puts forward a feasibility of improvement and optimization.

According to the proposition of the 7th National College Students Engineering Training Comprehensive Ability Competition, the paper systematically clarifies the structural design ideas of the thermally driven vehicle that meets the requirements of the competition, and designs a thermally driven vehicle that can realize autonomous walking accordingly. The core of the vehicle's design is the use of a Stirling engine to convert thermal energy into mechanical energy to power the drive vehicle, which is powered by burning liquid alcohol. This article relates the process of designing the thermally driven vehicle, applying cam as the steering mechanism, gears as the main transmission, and debugs and modifies the actual walking trajectory of the trolley is produced based on the structural design and kinematic simulation.

This article through to the elevator brake test check the practicability of the special equipment industry and needs a special surface plug gauge ruler tool consideration, study design a kind of special surface plug gauge ruler, which include the different thickness of the single chip surface plug gauge ruler, single chip surface made of stainless steel plug gauge ruler itself monolithic plug gauge ruler is in the shape of surface On the surface of the single piece curved plug gauge, the text and digital specifications of the calibration measurement are displayed, and the text and digital specifications are displayed for the clearance thickness and curved surface radian that can be calibrated. The research design of tool structure is simple, easy to carry, and easy to install and manufacturing, in addition, combined with the characteristics of surface plug gauge ruler, can be extended to other similar brake clearance measurement and inspection, possesses the advantages of convenient use, high maneuverability, improve brake maintenance and inspection can be quantified and practical security.

The performance of the transmission has a great influence on the power, economy and handling stability of vehicles, and the planetary gear automatic transmission is widely used in passenger cars because of its uniform force and compact structure. Therefore, in order to break the patent barriers, large enterprises are actively developing multi-speed transmissions, and the optimization of new topological structure has become the key of research and development. In this paper, the structural characteristics of four typical four-speed automatic transmissions composed of double-row planetary gears are analyzed, and their lever diagrams and shift schedules are deduced. Then, based on the lever diagrams, a new type of SC-CR transmission that uses only three clutches and two brakes to achieve four forward gears and one reverse gear is designed. What’s more, the specific topological structure is devised and the transmission parameters are optimized. The research shows that the equivalent lever speed line diagram and shift schedules of the four double-row four-speed planetary gear transmissions are basically the same. The transmission ratio of the new SC-CR four-speed automatic transmission is increased by 9.43% to 25.43%, the transmission ratio on gear D1 is increased by 8.86% to 18.51%, and the transmission ratio on gear D4 is reduced by 0.53% to 7.83%, which better realizes the optimization of transmission system. What’s more, through the series-parallel method, it can provide a better theoretical basis for the design of the new multi-speed planetary gear automatic transmission.

This paper presents an energy management strategy (EMS) using double Q-learning to reduce fuel consumption for hybrid electric vehicle (HEV). The ultimate goal of the EMS is to make the engine work in a high-efficiency zone by reasonably distributing mechanical energy from the engine and electrical energy from the power battery during the driving process of the vehicle, so that the vehicle can achieve optimal performance and achieve the purpose of reducing fuel consumption and emissions. Double Q-learning is a kind of reinforcement learning algorithms, which can avoid the maximization bias generated in Q-learning, so that the EMS can achieve better control effect. This paper simulates and compares the strategies including double Q-learning, rule-based, and Q-learning. The results demonstrate that the presented strategy can availably improve fuel economy and maintain the stability of SOC.

The vibration behaviors of composite laminated annular/circular sector plate with complex boundary conditions are discussed. Firstly, the overall displacement function and mid-plane displacement of laminated plates are constructed based on the Reddy's Higher order shear deformation theory (HSDT) and Jacobi polynomials method. Then, according to the elasticity of composite materials, the energy equation is expressed by mid-plane displacement. Finally, the vibration characteristics are derived by Rayleigh-Ritz technique. The fast convergence and accuracy of the method are verified by numerical examples. On this basis, the effects of spring stiffness values, material parameters and geometric parameters on the vibration characteristics of sector plate are fully investigated, which can be the benchmark for the future research.

The tightening bolt is a key component of the subsea clamp connector. Based on the working principle of the three-flap clamp connector, the research on the tightening bolt is carried out. Analysis of the mechanical transfer process of tightening bolts was conducted according to the formula for solving the torque and axial force of general bolts. The paper analyze the relation between the preload torque of the tightening bolt of the subsea clamp connector and the axial squeezing force on the metal seal. Verification of the theory accuracy was carried out by means of torque calculations and tests of the bolt. According to the tension-bending compound verification formula of the general bolt under working state, the deformation of the clamp and tightening bolt is solved by finite element simulation, so that the stiffness of the clamp and tightening bolt can be obtained by calculation, and the expression of the tension-bending compound verification of the tightening bolt under the working state is derived, which provides a reference for the design and verification of the tightening bolt of the subsea clamp connector.

Bio gel electric actuator (electric actuator) as a kind of smart material for artificial muscles, has the advantages of low driving voltage, large strain, good biocompatibility, good flexibility, low price, wide application prospect and high academic value, It has great potential application value in actuators, sensors, underwater robots and other offshore engineering and equipment fields. For example, a soft anchor lifting robot based on a dielectric elastomer actuator, and a flexible robot hand claw was made by using bionic artificial muscle. But the micro output force limits its application. In order to improve the output performance of the electric actuator, genipin was used to improve the preparation process of electric actuator in this paper, the effect of the electrically actuated film on the output performance of electric actuator was studied, and the mechanism of electric actuator output force enhancement was analyzed synthetically based on the change of elastic modulus and specific capacitance of the electrically actuated film after cross-linking.

Subsea clamp connectors enjoy wide application in the connection of equipment in subsea production systems due to their simple structure, low preload, and reliable performance. Aiming at the selection of engagement form of subsea clamp connector in the space, the engagement models under the kinetic schemes of straight slot and skewed slot are established in this paper; by comparing the feasibility of the two engagement kinetic schemes and analyzing their trajectories, it can be determined that the skewed-slotted structure has more advantages than the straight-slotted structure; by establishing the mechanical models of straight-slotted clamp and skewed-slotted clamp, the hub axial force required for the sealing state of the two engagement schemes are solved from the perspective of mechanical transfer by use of equilibriums of force and moment respectively, so as to derive the equations for the transformation of the preload of tightening bolt to the axial force of hub. Simulation and calculation of the clamp clamping force were carried out to verify the method of calculating the hub axial force from the bolt axial force. The comparison between theoretical and simulation analysis of bolt axial force and hub axial force is performed, although there are errors in the simulation results compared with the theoretical values, the validity of the solving expression and the reliability of the clamp connector studied in this paper can also be demonstrated to some extent.

Tensegrity can be used as a spatial deployable structure; the folding efficiency varies with different configurations. In order to optimize the axial expansion performance of the tensegrity and realize high compression rate This paper proposes a tensegrity structure based on curved bars. First of all, we establish the mathematical model of the single-layer tensegrity with curved bars. Then we analyze the two splicing forms of the single-layer basic unit, including node-tonode splicing and node-to-saddle cable splicing. After that, in the dynamic’s software, we analyze the kinematic characteristics of the single-layer and double-layer tensegrity with curved bars during the compressive and deployable process. We find that the deformation of the bar members is much obvious than the cable members during the compression and deployable process. Finally, through the quantification of the internal forces of various types of members, it is verified that the various components of the structure will not be damaged during the compression and deployable process.

In order to evaluate the reliability of subsea Christmas tree structure, a reliability analysis method based on fuzzy fault tree is proposed in this paper. First of all, by analyzing the configuration of the subsea Christmas tree from different manufacturers, the typical structure of the subsea Christmas tree is determined, and the failure tree model of the subsea Christmas tree structure is established based on the external load analysis. Then, the fuzzy comprehensive evaluation method is used to obtain the failure rate of the bottom event of the fault tree. The reliability indexes such as the failure rate of the top event, the reliability and the reliability life curve are calculated by quantitative analysis. Finally, the importance of the fault tree is analyzed. The results show that the key importance of "tree body inner wear" is the highest and has the greatest impact on the top event. It is a weak link in the structure and should be paid attention to. The research results can provide technical reference for the risk assessment of the subsea Christmas tree, and provide certain guiding significance for the design and manufacture of the subsea Christmas tree.

When a ship is running at sea, it will heave under the influence of wind and waves, which will affect the operation of Marine crane. This paper proposes a parallel semi-active heave compensation system for large tonnage offshore crane. In order to improve its compensation efficiency, an adaptive sliding mode controller is designed to control the compensation system. Firstly, the mathematical model of parallel semi-active heave compensation system is established, and the relationship between controller output and load displacement is obtained. On this basis, the sliding mode function and adaptive law are defined, and the mathematical model of adaptive sliding mode controller is constructed. According to the above mathematical model, the simulation model of the parallel semi-active heave compensation system is established and the simulation experiment is carried out. The simulation results show that the adaptive sliding mode controller designed in this paper can compensate the heave displacement of the load under the influence of sea waves, And has better compensation effect.

To analyze the characteristics of ring stiffened cylindrical shell in the design space, the full factorial experiment design method is used to obtain all feasible solutions in given ranges. The cylindrical shell has multiple objectives and variables, so the analysis of the characteristics of cylindrical shell is a multivariate analysis problem. Multivariate analysis approaches correlation analysis and cluster analysis are used to study the structural characteristics of ring-stiffened cylindrical shell. The results of multivariate analysis indicate the incompatibility of attributes and the similarity and complicated relations among attributes and variables of cylindrical shell. The useful conclusions obtained from multivariate analysis approaches can be used as reference in engineering design.

In this paper, the underwater towed system during the course-keeping motion was taken as the research object, in addition, the governing equation of motion was given as well. By the means of the experimental data obtained by the design of experiment, the second-order polynomial response surface models reflecting the steady-state motion characteristics of the towrope were established. Apart from mentioned above, the tail drag depth and the head tension were taken as objective functions, and the optimal solution set of Pareto was obtained by using the multi-objective optimization algorithm. The results shown that the approximate models were used to optimize the towrope when the parameters of the towrope were within a certain range, which can quickly and accurately analyzed the influences of each parameter on the steady-state motion characteristics of the towrope.

The marine gearbox generates huge vibration and noise due to excitation, which seriously affects performance evaluation and stealth during the working process. To solve the problem this article adds a vibration isolation system to the gearbox, explores the vibration and noise reduction performance of the 6 spring vibration isolation structures on the gearbox. Furthermore, not only the Block Lanczos method in the ABAQUS software is used to perform modal analysis and dynamic analysis on the gearbox, but also LMS Virtual. Lab acoustic simulation calculation software is used to analyze the noise of the gearbox. The results show that after adding a shock spring vibration damper to the bottom of the gearbox, the noise is reduced by 15%, which can effectively reduce the vibration and noise of the gearbox during operation.

The rational use of plate frame structure can improve the performance of ships. To study the mechanical properties of plate frame materials with different materials and thickness, in this paper, the different materials such as metal and composites, plate fiber thickness and total plate thickness are studied as the objects, a model is established, the parameter sensitivity of plate structure and stiffened plate structure are analyzed, and the influencing factors of structural vibration characteristics are explored. The results show that Poisson's ratio and elastic modulus are inversely proportional to the variation trend of structural vibration displacement response. The fiber thickness and plate thickness are inversely proportional to the changing trend of structural natural frequency. The thickness of the stiffened plate is directly proportional to the changing trend of natural frequency.

The dynamic characteristics of the ship's plate frame is an important factor in determining the structural quality of the ship. In this paper, the structural impact response spectrum and the deformation displacement of the plate structure under the blast load are used as indicators to assess the impact resistance. A finite element model of the plate structure and flow field is established. The dynamic characteristics of composite laminated plates with different characteristics under the underwater explosion loads are analyzed. The results show that the elastic modulus and Poisson’s ratio of the composite laminated, the number of layers, the fiber laying angle, all affect the mechanical properties and impact resistance of the plate structure.

A calculation method of interference fit between gear and hollow shaft is proposed, which is close to the finite element simulation results, and the effect of interference on contact stress and maximum Mises stress is further analyzed. The residual stress generated during the heat treatment of gear and hollow shaft and the dynamic load transmitted by the driving wheel are considered, and then the effects of residual stress and dynamic load on the interference fit between shaft and gear are studied. It is found that the magnitude of interference is linear with contact stress and maximum Mises stress. After adding residual stress, the relationship between residual stress and maximum Mises stress is nonlinear. Residual stress greater than 350MPa will cause plastic deformation of gear, resulting in weakening or even failure of interference fit connection. When the dynamic load is added, it can be found that the interference connection is further weakened, but the effect is smaller than the residual stress.

The adhesion of marine microorganisms to the surface of hulls and marine engineering facilities will induce a lot of serious problems. Therefore, the surface needs antifouling treatment, and the bionic materials with micro - rough surface microstructure can be applied in marine anti-biofouling. A series of hydroxy-terminated polybutadiene (HTPB) polyurethanes with different hard segment contents was synthesized by prepolymer method, then blended with epoxy resin, and the polymer coating with microstructure is prepared by cross-linking curing with amine cross-linking agent. The anti-biofouling and antibacterial properties of the low surface coating have been studied. The characterization analysis of the system was carried out through infrared (FTIR), ultra-depth of field three-dimensional microscope, contact angle measuring instrument and antibacterial test. The results show that the HTPB polybutadiene has formed a hill-like microstructure in the epoxy resin, the microstructure size is controllable, and the hydrophobic low surface energy coating can be prepared. There are regularly arranged microstructures with different sizes on the PU/EP coating surface with different hard segment contents. The maximum of the static water contact angle of the sample numbered HPE10 is 102°. Compared with pure PU and pure EP coatings, the static water contact angles of the micro-structured coatings are significantly increased, indicating that the coating has low surface energy and hydrophobicity, and the static water contact angle of the PU/EP coating is significantly increased after rubbing with sandpaper, up to 117°. Escherichia coli, Staphylococcus aureus, Vibrio natriegens and Citrobacter farmeri were selected for antibacterial tests, and the antibacterial test showed that the coating has high antibacterial properties against Escherichia coli and Staphylococcus aureus. This kind of antibacterial coating with low surface energy has good prospects for marine application development.

China is a country with the largest length of inland waterway. With the implementation of Three Gorges Reservoir, the shipping market is becoming increasingly active and inland waterway shipping has entered a good period of rapid development. However, the unstandardization and complexity of ships put forward higher requirements for navigation conditions of the channel, which increases the difficulty of ship control. In order to make ship handling safer, a large number of scholars have been attracted to study ship handling. Scholars have studied the wind effect, shore wall effect and ship to ship effect in various working conditions by means of theoretical research, ship test and numerical simulation, and obtained a large number of theoretical and empirical formulas in line with the actual situation. These results have very important guiding significance for ship handling safety.

When T22 ferritic steel and 800H austenitic alloy were welded, premature failures often appear on the heat-affected zone side of ferritic steel, due to carbon migration. The carbon chemical potential gradient is the driving force of carbon diffusion. Usually, adding a transition layer between dissimilar alloys is an effective way to reduce the chemical potential gradient. Therefore, in this study, thermodynamic and kinetic modeling tools were used for designing transition layers between T22 and 800H to mitigate carbon migration. Firstly, simulation results show that a linear transition zone can decrease the migration of carbon to reduce the decomposition of carbide on the T22 side. In addition, two layers transition was designed to further depress carbon migration. Compared with the wider linear transition zone, it can gain a similar favorable effect. Moreover, the width of the transition zone can be significantly minimized. The designed constant composition is propitious to drop the experiment complexity.

Through Solidworks software to establish the crane trolley three-dimensional model, using ANSYSWorkbench software on the key mechanism, impose reasonable constraints and load and statics analysis, calculate the distribution of stress and strain, verify the crane car key parts design rationality. The research results provide a theoretical basis for the design of a similar crane trolley.

Based on the motion principle of mechanical swing guide rod, a new spinning forming method for elliptical cross-section thin-walled parts is proposed. The mathematical model of forming principle and forming trajectory of elliptical cross-section thin-walled parts was established by graphical analysis method, and the accuracy of the model was verified by numerical calculation. Based on this model, the motion relationship between the wheel and the parts in the forming process is studied. The wheel rotation radius of different sizes is selected to simulate the motion trajectory of the wheel in the forming process of the elliptical cross-section thin-walled parts. It is found that when the wheel rotation radius is closer to its lower limit value, it is conducive to the forming of the elliptical cross-section parts, which provides a theoretical basis for the general process research and application of the relevant sections and the development of machine tools.

When T22 ferritic steel and 800H austenitic alloy were welded, premature failures often appear on the heat-affected zone side of ferritic steel, due to carbon migration. The carbon chemical potential gradient is the driving force of carbon diffusion. Usually, adding a transition layer between dissimilar alloys is an effective way to reduce the chemical potential gradient. Therefore, in this study, thermodynamic and kinetic modeling tools were used for designing transition layers between T22 and 800H to mitigate carbon migration. Firstly, simulation results show that a linear transition zone can decrease the migration of carbon to reduce the decomposition of carbide on the T22 side. In addition, two layers transition was designed to further depress carbon migration. Compared with the wider linear transition zone, it can gain a similar favorable effect. Moreover, the width of the transition zone can be significantly minimized. The designed constant composition is propitious to drop the experiment complexity.

This paper introduces the development of vacuum suction wall climbing robots, discusses the characteristics of common suction cups and corrugated suction cups, explains the advantages and disadvantages of corrugated suction cups, establishes a suction model to verify the advantages of corrugated suction cups in terms of suction performance, achieves directional control of suction cup deformation by using different materials on the same suction cup with reference to the characteristics of pneumatic flexible structures, improves some aspects of the deficiencies of common corrugated suction cups, thus optimising the This improves some aspects of the conventional corrugated suction cups, thus optimising the stability of the robot equipped with these suction cups and strengthening the suction cup structure. The 3D model of the suction cup structure before and after the improvement is imported into the ansys finite element simulation platform, and the finite element simulation model is established through the static analysis environment for analysis. The comparison of the deformation data in all directions of the suction cup before and after the improvement, as well as the total deformation, total stress and total strain of the suction cup are obtained, which verifies the feasibility of the optimisation method.

With the use of the nose landing gear, its friction parts will generate clearance due to wear, affecting the stability of the aircraft shimmy. This clearance is a complex situation where both axial and radial clearances exist, but it has not been investigated in the current study. Herein, we analyze the location between the upper and lower torque links, which are prone to wear, and proposed axial clearance models and radial clearance models applicable to the location. Furthermore, we simulate and analyze the influence of the single radial clearance case, single axial clearance case, and radial clearance and axial clearance coupling case on the nose landing gear shimmy stability with the critical anti-shimmy damping coefficient as the evaluation index. The results show that the radial clearance at the upper and lower torque links has no significant effect on the shimmy stability of the nose landing gear, while the increase of the axial clearance will increase the critical anti-shimmy damping coefficient and reduce the shimmy stability. And when the anti-shimmy damping design is 400Nꞏmꞏs/rad, the axial clearance between the upper and lower torque links should not exceed 0.54mm, otherwise, periodic ±0.08° reciprocating rotation will occur between the inner cylinder and the outer cylinder. The larger the axial clearance, the larger the reciprocating torsional Angle will be. These works provide a reference for the design and maintenance of the nose landing gear.

Given the low precision of the metering and filling system in the current rubber powder packaging equipment on the market, this paper is studied and improved. First, the physical properties of the rubber powder were tested. Secondly, the error of the metering and filling process is analyzed, and the control strategy of the three-stage screw feeding is put forward.

According to the difficulty of cutting the ZTC4 material, slot cutting experiments were designed and three directional dynamic milling force were obtained. Instantaneous milling force model and multiple linear regression was used to analyze three directional milling force coefficients and edge milling force coefficients. To evaluate the performance of the dynamic milling force model, a new slot cutting experiment was designed. The comparison of simulations and experiments indicates the average milling force error are 5.74%, 3.93%, 7.98%, the dynamic milling force prediction model fits well in cycle, trend and amplitude. The feasibility and accuracy of the model for predicting the instantaneous milling force is verified.

To study the mechanical damage of sesame seeds in planting, harvesting and threshing, the static compression test and finite element simulation were carried out on Zhengzhi HL05 sesame seeds. Based on the experimental results, given the same moisture content, sesame seeds have the largest crushing load under flat compression, the second largest crushing load under lateral compression and the smallest load under vertical compression; when the loading direction is the same, the elastic modulus, maximum deformation and crushing load decrease with the increase of moisture content; the elastic modulus of sesame seeds is within the range of 1.64MPa-7.06MPa, the maximum deformation ranges from 0.23mm to 1.05mm, and the crushing load varies from 1.84N to 12.9N. Mechanical modeling and finite element simulation of sesame seeds based on 3D laser scanning technology explains the crushing mechanism of sesame seeds more intuitively, with the maximum error between the simulation and the experiment being less than 7%, which verifies the feasibility and accuracy of modeling based on 3D laser scanning technology, and provides a new method for modeling small-sized and irregular-shaped agricultural products.

Bionic robot fish (Body and/or Caudal fin (BCF)) is a bionic robot fish propelled by Body and/or caudal fin (BCF). It has the advantages of high speed, efficiency and high mobility, and is the focus of bionic robot fish development in recent years. In this paper, skipjack bonito with crescent caudal fin and swimming pattern of Jacks was selected as biomimetic object. By collecting the body proportion and characteristics of skipjack bonito, the overall shell design of the bionic robot fish was carried out, and a multi-degree of freedom and multi-joint caudal fin was designed to realize various underwater movements of the robot fish.

To solve the problem of poor systematization and ambiguous input of agricultural machinery in requirement analysis， using MBSE theory combined with the development and design of key mechanisms for automated cuttings equipment, an improved method of requirement analysis for automated cuttings equipment is proposed. By refining participant requirements, a natural language description of the set of user requirements is generated. An itemized set of requirements with standard information is constructed by the proposed semantic model for the standardization of requirements. At the same time, the requirements are verified based on the activity diagram in SysML using a logic simulation method to update the entry set of requirements. On this basis, the requirement model of the key mechanism of the automated cuttings equipment is created by SysML, and the input of the mechanical design information data flow is realized. The results show that the method improves the development process from initial requirements to requirement models, ensures consistency and traceability between the two, and can provide a design basis for the development of automated cuttings equipment.

Multi-gear planetary gear transmission has become a research and development hot spot of automobile enterprises, and excellent transmission topological structure determines the automobile transmission performance, Therefore, it is of great significance to research and develop new transmission topological structure. Firstly, this paper analyzes the structural characteristics of common seven-speed transmission, and puts forward a topological structure of three-row series-parallel seven-speed automatic transmission, which consists of an SS-CR double-row parallel structure and a single-row double-stage planetary row series-parallel connection, and can realize seven forward gears and one reverse gear with only six shift elements. On this basis, the equivalent lever diagram and the speed diagram are designed, and the transmission parameters of each gear are calculated in detail and optimized by using the triangle similarity principle. The results show that only two shift elements are required for each gear of the new transmission. And in addition to the conventional step-by-step lifting gear, spanning lifting gear can be realized between D1-D4 and D5, between D4 and D6, and between D5 and D7. Its transmission ratio range is 9.77, which is 64.02% higher than that of Mercedes-Benz 722.9. The transmission ratio of the lowest gear D1 is 3.76% higher and that of the highest gear D7 is 36.74% lower.

Based on machine vision, the crane transports items from the pick-up area to the stacking area according to the general rules through an autonomous, orderly and precise control method throughout the process. Through the research and analysis of the existing gantry cranes for transporting and placing goods, a new type of gantry crane is developed by using synchronous belt drive instead of rope lifting, creatively building diamond-shaped tracks and improving work efficiency. The crane has the characteristics of fully automatic operation, precise operation and novel structure, which conforms to the development trend of automated terminals in the current era.

In this paper, the phenomenon of abnormal jitter of the left rear door is studied, while a certain SUV of domestic brand driving on the washboard pavement with the speed in between 11 and 13km/h. The abnormal shaking of rear door is caused by the excitation of four tires by the preliminary test. The inverse sub-structuring analysis method was introduced to analyze the vibration transmission path between spindle head and the left rear door. The advantage of the method which can obtain the dynamic parameters of the interface between chassis system and vehicle body system, the frequency response function of substructures without decoupling the system. Then excitation transmissibility from each spindle head to the attachment point (the passive side) and non-coupling FRF of each substructure are calculated. The contribution of vibration transmission path is further analyzed. In final, the higher excitation transmissibility of the attachment point is found.

In order to locate vibration source caused by the wing fault through the human body feeling in the passenger cabin of the airplane, human comfort is selected as the evaluation index. Based on the method of evaluating human comfort according to ISO 2631-1-1997 standard, the response data of seats in the cabin of an aircraft under different vibration sources are analyzed. The human comfort of different seats under the excitation of horizontal tail, vertical tail, flap and aileron is obtained. The comfort level is divided into several grades according to the standard. The results show that for the excitation at the horizontal tail and vertical tail, the level distributions of human comfort at different seats is unique, so it can be used to judge the abnormal excitation at these two places. When the flaps and ailerons are excited, there is no such unique distribution in the comfort index of each position. The results of this paper can be used for on-line rapid identification of aircraft wing vibration sources.

A legged lunar-based equipment (LBE) with buffering and walking capabilities is proposed according to the requirements of complex tasks on the lunar surface. The design and function realization principle of the RU-2RUS parallel leg are introduced, and the multi-state pose is designed. The kinematics model of a single chain is constructed by using the improved DH method. The kinematics of the mechanism is solved through the geometric relationship. Then, the single-leg workspace is obtained and analyzed to verify the rationality of the configuration. The results show that the motion range is large, and the adjustment required for state switching is minor. It can provide a feasible lunar-based equipment design scheme for lunar surface stable landing, material transfer, multipoint detection, and base construction.

The increasing drilling depths of oil and gas wells make the load conditions of drill strings more and more severe. Using titanium alloy drill pipe can effectively reduce hook load and improve the safety margin of wellhead drill pipe. The tool joint is the weak link of drill string. However, there are few researches on mechanical properties of titanium alloy tool joint under complex loads. In view of the above, a three-dimensional finite element model of double shoulder titanium alloy tool joint was established by ABAQUS software, and its ultimate tensile and torsional capacities and the mechanical properties were analyzed under complex loads (make-up torque, axial tension, bending moment and internal pressure). The results show that the maximum von Mises stress of titanium alloy tool joint under complex loads is less than the ultimate strength of material, thus the tool joint meets the requirements of applied load conditions. By determining the ultimate tensile load and ultimate working torque of tool joint, it can provide a significant reference for selecting the axial tension and working torque reasonably and avoiding the failure of titanium alloy tool joint.

Ice-sugar gourd as a symbol has the festival season, is the carrier of Chinese traditional culture, was deeply loved by national and foreign people. At the moment, sugar-coated berry mainly was made manually and the production efficiency is low. There is no sugar-coated berry of the fully automatic production equipment to meet the needs of producing sugarcoated berry string automatically. Based on the requirement of automatically ice-sugar gourd string producing, the device composed of three basic function modules, bamboo pole transporting, hawthorn transporting and stringing together of hawthorn was brought out. The electromechanical integration solution supported by pneumatic control system was designed. The flow chart of pneumatic control system was built combining with the producing process and systematic structure. The pneumatic control circuit was simulated and debugged by using FluidSim simulation software and the corresponding control program was designed based on CX Programmer software. The pneumatic control solution and designing method of the automatic Ice-sugar gourd device were proposed, which provided the engineering practice basis for further increasing the automatic picking and conveying of bamboo sticks and realizing the integrity design and development of Ice-sugar gourd production line.

Structure rules for mining vessels are known less for designers. This research firstly introduces the basic functions and normal operating conditions for mining vessels, from which we find that mining vessels are similar to FPSO /FDPSO and bulk carriers. The similarities and differences between mining vessels and FPSO/FDPSO and bulk carriers are then summarized, and CCS [1-3], ABS[4], DNV[5], BV[6], etc. structure rules are also analyzed. The hold of a mining vessel is loaded by ore, which, in terms of the physical characteristics, is similar to a bulk carrier. Meanwhile, a mining vessel requires long-term mining, which is similar to FPSO and FDPSO. So the structure technique character of mining vessels must meet both bulk carriers and FPSO requitements. This paper tends to form some basic structure rules for mining vessels.

This paper mainly introduces the design of the control system part in the thermal performance test of the solar collector, including 3 functional modules as test bench automatic tracking control system, automatic flow control system and temperature control system. Through verification, it can meet the test requirements of the standard GB/T4271-2007 "Test Methods for Thermal Performance of Solar Collectors".

In order to study the influence of wheel tread wear on bogie vibration transmission of high-speed EMUs. Master the law of a certain type of EMU changes with the operating environment and service status. In order to further expand the operation range of 350 km/h of a certain type of EMU, the a certain type of EMU performance optimization and operation quality improvement provide support. It provides the basis for the optimization of maintenance and repair program. Based on the long-term dynamic service tracking test of the type A and type B EMUs of station A, the wheel wear and vibration transmission of key components of bogie are analyzed in this paper. The running performance of the EMU and the vibration evolution law of the key components of the bogie under the condition of wheel wear are obtained, which provides a basis for deepening the basic theory of high-speed rail and the research on 400 km/h high-speed rail technology.

In order to study the influence of sleeper spacing on the mechanical properties of steel spring floating slab track bed, taking a subway project as an example, the finite element static model of steel spring floating slab track established by finite element software is used to simulate the action of train load, and the stress and deformation characteristics of rail and floating slab concrete under three load combinations and 335 calculation conditions are analyzed. The research shows that: (1) When there is no lateral force, the stress and deformation of the rail under the designed sleeper spacing(DSS) are basically the same as that under the imaginary sleeper spacing(ISS); when the lateral force acts, the regular sleeper spacing can reduce the deformation of the track structure to a certain extent. (2) The lateral and vertical axle load have little influence on the displacement of steel spring floating slab. The relative variation difference under different sleeper spacing is less than 5%, but the relative variation amplitude of concrete stress of floating slab is about 20%. (3) Based on the analysis results of stress and deformation characteristics of rail and floating slab, the relative difference of rail deformation and stress is less than 5%, the stress increment amplitude of floating slab is less than 0.35Mpa, and the relative difference of displacement is within 12%.

In order to improve the assembly efficiency and assembly quality of TR modules in the electrical equipment, an automatic assembly method for a precision TR module is proposed in this paper. Based on the analysis of the TR module automatic assembly process, the automatic assembly platform with self-sensing ability is designed, and the automatic assembly test is carried out to obtain the key process data such as the maximum press-mounting force in different stages of the TR module automatic assembly. In view of the changing trend of the press-mounting force in the assembly process, a detailed reason analysis is carried out. Based on a large number of test and analysis results, an online real-time quality control measure for the TR module automatic assembly is obtained. The practical application results show that the TR module automatic assembly method proposed in this paper is reliable and effective.

At present, Metro and other urban rail transit are in the period of high-speed development opportunity. The demand of high-quality travel puts forward higher requirements for the stability and comfort of Metro vehicles. The vibration of running vehicles will do harm to passengers’ physical and mental health and ride experience and, which also affect the operation efficiency of Rail Transit. In this paper, firstly, the dynamic performance test of a type AH metro vehicle is carried out. According to GB/T5599-2019 and other standards, the hunting stability and ride quality of the vehicle under empty load and normal working condition of air spring are evaluated. The test results show that the hunting stability (safety) index of the vehicle meets the evaluation standard. The sperling index is excellent, and there is no lateral instability of bogies. Secondly, the relationship between vibration characteristics and vibration transmission of vehicle bogies is expounded.

As an important parameter of the vehicle, the relationship between the tread equivalent conicity and the vibration of bogie for EMU is very valuable and significant for research. In this paper, a tracking test is carried out on the EMU running on a certain line to analyze the equivalent conicity and frame vibration of the vehicle. The evolution law of the equivalent conicity and the relationship between frame vibration and repair cycle and operating mileage during the tracking test of the vehicle are obtained, which provides a certain foundation for deepening the basic theory of high-speed rail and the technical research of high-speed rail with a speed of 400 kilometers in time.

With the promotion of the " global sulphur limit", maritime regulatory departments around the world need to supervise the sulphur content of fuel oil used by ships. How to efficiently carry out the monitoring and supervision of sulphur content of Marine fuel oil is the main problem we are facing at present. Provide technical support for the monitoring and supervision of sulphur content in Marine fuel, this study used the real-time monitoring of SO2 and CO2 to estimate the sulfur content of the fuel, and conducted a statistical analysis of the deviation degree of the test results. The results show that the sulfur dioxide and carbon dioxide concentrations are stable in calculating the sulfur content of ship fuel; the uncertainty range of the sulfur-to-carbon ratio used in supervision for compliance determination is not less than 10%.

Limited by the complexity of the mechanism of the pumping pipeline and the construction environment in the pumping pipeline during the process of pumping out the shore, it is impossible to allow precise measuring instruments to measure internally. In the past, domestic and foreign scholars only used key equipment such as mud pumps. Work characteristics are studied and related mechanism models are established. In view of this situation, the mechanism analysis of the trailing suction dredger and the calculation method of the mechanism model are carried out, combined with the existing research results and engineering experience, the water layer model and empirical formula are used to obtain this working condition. Under the mechanism model of the extraction of the cabin pipeline, the key parameters of the extraction of the cabin obtained by the mechanism model are verified by the CFD (Computational Fluid Dynamics) software. The results show that the key parameters of bank extraction and bank blowing calculated based on the mathematical model obtained from the mechanism analysis are put into the CFD software and the results obtained are generally in line with reality. It provides a way for future research on the mechanism of the pumping and bank blowing of the trailing suction dredger. Mathematical model reference.

Intelligent polishing equipment comprising industrial robots and sensors is increasingly used to polish ship components, which has traditionally been done manually. The core component of such equipment is the visual recognition system, which is responsible for workpiece recognition and positioning, and polishing point recognition and extraction. Current systems are mostly based on CCD or CMOS cameras with 2D image processing. However, recognition efficacy is limited by the auxiliary lighting conditions and image resolution, and depth information cannot be obtained. An algorithm module is designed for object recognition in point cloud from a depth camera in a device used to polish small ship components. The module’s architecture and the functions of the visual recognition system are described. The module’s functions are based on the OpenCV and printer control language (PCL) libraries and are implemented in the C++ programming language. An algorithm test platform was built to verify the algorithm module its functions, including camera pose estimation and coordinate transformation, point cloud segmentation, centroid extraction, and edge extraction. The limitations of on-site auxiliary light conditions and image resolution were overcome. A workpiece recognition and positioning success rate of 98% was achieved, and the polishing point detection and recognition accuracy are sufficient for real applications. This allows accurate and comprehensive visual data to be provided to the automated polishing device, ensuring smooth operation and effective workpiece handling and polishing.

Traditional identification for the AUV dynamic models is based on the least square method. But it’s time-consuming and expensive. Especially, the intervention AUV is complex to identify the dynamic models. The paper identifies dynamic models for the intervention AUV based on numerical simulation. The paper uses the software “Star CCM+” as a tool. To further improve the identification precision for hydrodynamic damping coefficients, the paper modifies the virtual tank boundary function and AUV surface function in the simulation. Experiments on heading and longitudinal motion trajectory are conducted to verify the identification effectiveness of the improved computational fluid dynamics (CFD) method compared with that of the traditional least square method.

In order to improve the loading optimization efficiency of the pipe fitting pallet assembly in the ship pipe processing workshop, the loading problem of the pipe processing workshop was studied for the low efficiency of pipe pallet transportation in the traditional workshop, and a mathematical model of loading with the goal of maximizing space utilization was established. According to the characteristics of pipe fittings and fusion of heuristic search methods, an improved genetic algorithm is proposed to solve the optimization problem of ship pipe fittings, and the effectiveness and practicability of the algorithm are verified through experiments.

Passive wave compensation (PHC) is widely used in offshore resource exploitation, with a series of advantages such as improved operating window. However, the structures which are in the splash zone will often be damaged. Appropriate PHC's system parameters can improve the compensation efficiency in specific sea conditions. In this paper, based on the theory of potential flow, the slamming force prediction model, the PHC system model and the coupling model are proposed. Through numerical simulation, the results show that: (1) PHC can also compensate the slamming force; (2) Impact of slamming force on compensation efficiency. Based on the numerical simulation and analysis,new ideas is provided for the selection of PHC's parameters.

Self-excited oscillating pulsed cavitation jet is a phenomenon in which cavitation bubbles are generated by oscillation in the unique structural characteristics of the nozzle, and the impact effect of the jet is increased by collapse of the cavitation bubbles. Based on the structure parameters of the traditional Helmholtz and organ pipe single chamber self excited oscillating pulsed nozzles, Helmholtz + Helmholtz, Organ pipe + Organ pipe and Helmholtz + Organ pipe dual chamber self-excited oscillating pulsed nozzles with different structures are established in series, and VOF (Volume of Fluid) is selected for multiphase transient flow calculation. The external flow field of dual chamber is studied to obtain the best combination nozzle.

The dock shop hoisting is the core link in the shipbuilding process. However, due to the large number of constraints in the dock shop hoisting process, existing means cannot be applied to make reasonable hoisting program. Aiming at the dock hoisting process, this paper adopted oriented graph and AOE network planning technology to establish a hoisting network problem model. The energy consumption caused by the operation of the gantry crane during the hoisting process considered, and the paper took the optimization of the green hoisting process as the goal. To solve this problem, an improved genetic algorithm was designed and then compared with the traditional genetic algorithm. The applicability of the improved genetic algorithm was demonstrated. Finally, this algorithm was applied to a specific example to demonstrate that the improved genetic algorithm is feasible and effective to solve the problem of dock hoisting process optimization.

The kinematic response of the reinforced cylindrical hull has a significant impact on the comfort of the ship's occupants. The dry modal data are first decomposed into multiple IMF signals using the empirical modal decomposition method, and the noise and trend terms in the signals are removed, with the energy increment method. The LSCE method is then used to plot the frequency stability of the modes at different measurement points, and after eliminating spurious modes, the final identified model intrinsic frequencies are obtained; Finally, the effectiveness of the analytical solution in identifying the inherent frequencies of the model is verified by comparing it with the inherent frequencies obtained using the analytical solution.

The operating status of submarine cables directly affects the safe and reliable operation of offshore engineering. It is of significance to timely and effectively obtain the health status of submarine cables. Due to the complex structure and operating environment of submarine cables, it is difficult to accurately obtain the health status of submarine cables. Therefore, a health status assessment of submarine cables based on multi-state quantity fusion is proposed. Firstly, following technical guidelines of cable status evaluation, an index system suitable for submarine cable comprehensive health status evaluation is constructed by integrating static data, such as patrol inspection and testing data, and dynamic data from online monitoring. Secondly, a set of reasonable and evidence-based evaluation criteria is formed based on the characteristics of online monitoring status of submarine cable and evaluation standards from cable guidelines. Then, on the basis of the above, a multi-state fusion based status evaluation model is established, which can evaluate the overall submarine cable as well as its components hierarchically to obtain its health status. Further leveraging fuzzy theory, a comprehensive health status of the submarine cable can be obtained. Finally, the feasibility and effectiveness of the proposed method is verified by applying on submarine cables in a practical offshore oil and gas project.

In order to shorten the hangar-exporting time of shipboard helicopter, the optimization of shipborne helicopter hangarexporting scheduling was studied. Firstly, the mathematic model of the shipboard helicopter hangar-exporting optimization is established. Secondly, based on the genetic algorithm, the algorithm for solving the schedule problem of shipborne helicopter out of the hangar is completed. Finally, the algorithm is verified by a case study. The case shows that the model and algorithm are feasible to get an optimal solution of the shipboard helicopter hangar-exporting scheduling.

Underwater drag reduction technology is one of the key ways to break through the ocean-going problem, and the bionic drag reduction is very promising in many types of drag reduction method. The bionic drag reduction is using the gasliquid interface slip effect, while the film is very unstable, leading to drag reduction function failure. The concave corner microstructure of springtail cuticle can make the air retention, which has very important significance to solve the problem of instability of gas film. In this paper, a simplified model is established by referring to the concave corner microstructures of springtail cuticle. The k-ε turbulence model is coupled with VOF method is used to establish a simulation model. The simulation results show that: with the increase in free shear area ratio, the drag reduction rate of the microstructure increases; the drag reduction rate of different microstructure is slightly different, but it is mainly related to the free shear area ratio.

This paper proposes a lightweight network for ship detection based on YOLOV3. This method reduces the parameters and model size of YOLOV3 while retaining accuracy from three aspects. First, an efficient way is described of replacing the Darknet-53 of YOLOV3 with a reduced network. Second, an optimization form is demonstrated to improve the basic unit. Last, compression and acceleration strategies are implemented in the method. The performance of our method and YOLOV3 is measured on a self-built dataset for ship detection. The method we proposed is 29× less parameters, 85× less size, and 3× less inference time than YOLOV3. In the experiment, the method is deployed on a Qihang Unmanned Surface Vehicle (USV) and realizes real-time detection of ships.