Dr. Shiv Joshi Profile

Dr. Shiv Joshi

Associate Professor at NextGen Aeronautics Inc

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Author

Publications (19)

Proceedings Article | 4 April 2017 Paper

Challenges and the state of the technology for printed sensor arrays for structural monitoring

Shiv Joshi, Scott Bland, Robert DeMott, Nickolas Anderson, Gregory Jursich

Proceedings Volume 10166, 101660H (2017) https://doi.org/10.1117/12.2263922

KEYWORDS: Sensors, Printing, Electronics, Manufacturing, Structural monitoring, Inkjet technology, Multiplexing, Transistors, Resistance, Dielectrics, Silver, Carbon, Data acquisition

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Proceedings Article | 29 March 2010 Paper

Modeling of a high-deformation shape memory polymer locking link

William Clark, John Brigham, Changki Mo, Shiv Joshi

Proceedings Volume 7645, 764507 (2010) https://doi.org/10.1117/12.847987

KEYWORDS: Shape memory polymers, 3D modeling, Finite element methods, Fluctuations and noise, Mechanics, Numerical analysis, Skin, Composites, Aluminum, Robotics

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Proceedings Article | 21 April 2008 Paper

Detection of disbonds in a honeycomb composite structure using guided waves

Harsh Baid, Sauvik Banerjee, Shiv Joshi, Siddhartha Mal

Proceedings Volume 6935, 693504 (2008) https://doi.org/10.1117/12.776349

KEYWORDS: Composites, Waveguides, Skin, Transducers, Aerospace engineering, Ultrasonics, Aircraft structures, Ultrasonography, Wave plates, Receivers

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Proceedings Article | 2 April 2008 Paper

3D FEA simulation of segmented reinforcement variable stiffness composites

C. Henry, G. McKnight, A. Enke, R. Bortolin, S. Joshi

Proceedings Volume 6929, 69290X (2008) https://doi.org/10.1117/12.778891

KEYWORDS: Composites, 3D modeling, Kinematics, Shape memory polymers, Finite element methods, Strain analysis, Matrices, Systems modeling, Homogenization, Aluminum

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Reconfigurable and morphing structures may provide significant improvement in overall platform performance through optimization over broad operating conditions. The realization of this concept requires structures, which can accommodate the large deformations necessary with modest weight and strength penalties. Other studies suggest morphing structures need new materials to realize the benefits that morphing may provide. To help meet this need, we have developed novel composite materials based on specially designed segmented reinforcement and shape memory polymer matrices that provide unique combinations of deformation and stiffness properties. To tailor and optimize the design and fabrication of these materials for particular structural applications, one must understand the envelope of morphing material properties as a function of microstructural architecture and constituent properties. Here we extend our previous simulations of these materials by using 3D models to predict stiffness and deformation properties in variable stiffness segmented composite materials. To understand the effect of various geometry tradeoffs and constituent properties on the elastic stiffness in both the high and low stiffness states, we have performed a trade study using a commercial FEA analysis package. The modulus tensor is constructed and deformation properties are computed from representative volume elements (RVE) in which all (6) basic loading conditions are applied. Our test matrix consisted of four composite RVE geometries modeled using combinations of 5 SMP and 3 reinforcement elastic moduli. Effective composite stiffness and deformation results confirm earlier evidence of the essential performance tradeoffs of reduced stiffness for increasing reversible strain accommodation with especially heavy dependencies on matrix modulus and microstructural architecture. Furthermore, our results show these laminar materials are generally orthotropic and indicate that previous calculations of matrix gap and interlaminar strains based on kinematic approximations are accurate to within 10-20% for many material systems. We compare these models with experimental results for a narrow geometry and material set to show the accuracy of the models as compared to physical materials. Our simulations indicate that improved shape memory polymer materials could enable a composite material that can accommodate ~30% strain with a cold state stiffness of ~30GPa. This would improve the current state of the art 5-10x and significantly reduce the weight and stiffness costs of using a morphing component.

Proceedings Article | 5 May 2005 Paper

Mechanical properties of shape memory polymers for morphing aircraft applications

Michelle Keihl, Robert Bortolin, Brian Sanders, Shiv Joshi, Zeb Tidwell

Proceedings Volume 5762, (2005) https://doi.org/10.1117/12.600569

KEYWORDS: Skin, Polymers, Shape memory polymers, Data acquisition, Glasses, Aerodynamics, Control systems, Laser induced plasma spectroscopy, Composites, Manufacturing

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Proceedings Article | 12 June 2000 Paper

Embedding of MEMS pressure and temperature sensors in carbon fiber composites: a manufacturing approach

Amir Javidinejad, Shiv Joshi

Proceedings Volume 3986, (2000) https://doi.org/10.1117/12.388101

KEYWORDS: Sensors, Composites, Temperature sensors, Carbon, Adhesives, Manufacturing, Lead, Microelectromechanical systems, Fiber optics sensors, Fabrication

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Proceedings Article | 9 July 1999 Paper

Electromagnetically coupled embedded sensors

Kissoo Jung, Jonathan Bredow, Shiv Joshi

Proceedings Volume 3674, (1999) https://doi.org/10.1117/12.351550

KEYWORDS: Sensors, Composites, Transducers, Modulation, Integrated circuits, Antennas, Data transmission, Inductive coupling, Carbon, Interfaces

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Proceedings Article | 9 June 1999 Paper

Application of electrically conductive thermoplastic adhesive film for design and manufacturing of smart structures

Amir Javidinejad, Shiv Joshi, Panayiotis Shiakolas

Proceedings Volume 3668, (1999) https://doi.org/10.1117/12.350744

KEYWORDS: Composites, Copper, Adhesives, Manufacturing, Smart structures, Resistance, Glasses, Design for manufacturability, Sensors, Optical fibers

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Proceedings Article | 6 June 1997 Paper

Conductivity of CFRP as a tool for health and usage monitoring

Ruediger Schueler, Shiv Joshi, Karl Schulte

Proceedings Volume 3041, (1997) https://doi.org/10.1117/12.275720

KEYWORDS: Electrodes, Carbon, Composites, Anisotropy, Optical fibers, Resistance, Tomography, Chemical elements, Finite element methods, Reconstruction algorithms

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Proceedings Article | 23 May 1997 Paper

Potential hypersonic-vehicle maneuvering concepts using smart structures

James August, Shiv Joshi

Proceedings Volume 3044, (1997) https://doi.org/10.1117/12.274702

KEYWORDS: Smart materials, Missiles, Smart structures, Actuators, Nose, Aerodynamics, Shape memory alloys, Bladder, Vehicle control, Motion measurement

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Proceedings Article | 31 May 1996 Paper

Numerical modeling of PZT nonlinear electromechanical behavior

Alex Freeman, Shiv Joshi

Proceedings Volume 2715, (1996) https://doi.org/10.1117/12.240835

KEYWORDS: Polarization, Switching, Ferroelectric materials, Data modeling, Ceramics, Numerical modeling, Systems modeling, Switches, Computer simulations, Lead

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Proceedings Article | 30 May 1996 Paper

Impact location, energy, and damage detection in a smart structure

Shiv Joshi, Nasir Munir

Proceedings Volume 2718, (1996) https://doi.org/10.1117/12.240860

KEYWORDS: Sensors, Neural networks, Damage detection, Smart structures, Linear filtering, Neurons, Image classification, Acoustics, Aerospace engineering, Manufacturing

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Proceedings Article | 1 May 1996 Paper

Preliminary design of smart structure fins for high-speed missiles

James August, Shiv Joshi

Proceedings Volume 2721, (1996) https://doi.org/10.1117/12.239116

KEYWORDS: Missiles, Actuators, Aerodynamics, Smart structures, Control systems, Structural design, Chemical elements, Shape memory alloys, Diamond, Solids

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Proceedings Article | 1 May 1996 Paper

Smart structures applications for hypersonic vehicles

James August, Shiv Joshi

Proceedings Volume 2721, (1996) https://doi.org/10.1117/12.239142

KEYWORDS: Missiles, Smart structures, Actuators, Smart materials, Shape memory alloys, Vehicle control, Aerospace engineering, Skin, Structural design, Active vibration control

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Proceedings Article | 8 May 1995 Paper

Feasibility study on phased array of interdigital mesoscale transducers for health monitoring of smart structures

Shiv Joshi

Proceedings Volume 2443, (1995) https://doi.org/10.1117/12.208262

KEYWORDS: Transducers, Acoustics, Signal to noise ratio, Phased arrays, Damage detection, Beam steering, Nondestructive evaluation, Phase shifts, Near field, Smart structures

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Proceedings Article | 5 May 1995 Paper

Finite element simulation of bulk elastic waves in piezoceramic transducers using interdigital electrodes

Mohammad Moetakef, Shiv Joshi, Kent Lawrence

Proceedings Volume 2442, (1995) https://doi.org/10.1117/12.208839

KEYWORDS: Transducers, Electrodes, Wave plates, Ultrasonics, Aluminum, Beam steering, Receivers, Transmitters, Smart structures, Nondestructive evaluation

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Proceedings Article | 6 May 1994 Paper

Dynamic actuation by surface-mounted piezoceramic patches

Shiv Joshi, Chih Fang

Proceedings Volume 2190, (1994) https://doi.org/10.1117/12.175215

KEYWORDS: Sensors, Transducers, Velocity measurements, Actuators, 3D modeling, Damage detection, Fermium, Frequency modulation, Signal processing, Aluminum

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Proceedings Article | 8 September 1993 Paper

Structural response of plates with piezoceramic layers

Dipen Shah, Shiv Joshi, Wen Chan

Proceedings Volume 1917, (1993) https://doi.org/10.1117/12.152778

KEYWORDS: Aluminum, Smart structures, Intelligence systems, Interfaces, Finite element methods, Sensors, Chemical elements, Information operations, Composites, Actuators

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Proceedings Article | 12 July 1993 Paper

Study of smart-sensing elements in a dynamic stress field

John Mannas, Shiv Joshi

Proceedings Volume 1918, (1993) https://doi.org/10.1117/12.147983

KEYWORDS: Sensors, Composites, Process control, Piezoelectric effects, Wave plates, Smart materials, Computer simulations, Electric field sensors, Smart structures, Actuators

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Showing 5 of 19 publications

Conference Committee Involvement (2)

Second International Conference on Smart Materials and Nanotechnology in Engineering

8 July 2009 | Weihai, China

Smart Nondestructive Evaluation and Health Monitoring of Structural and Biological Systems

3 March 2003 | San Diego, California, United States

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