Stress failure vignettes: errors of 10,000, the help of Humpty-Dumpty, and others

John W. Pepi

doi:10.1117/12.2066942

13 November 2014 Stress failure vignettes: errors of 10,000, the help of Humpty-Dumpty, and others

John W. Pepi

Proceedings Volume 9197, An Optical Believe It or Not: Key Lessons Learned III; 91970G (2014) https://doi.org/10.1117/12.2066942
Event: SPIE Optical Engineering + Applications, 2014, San Diego, California, United States

Abstract

In the latter part of the 1980’s, an all glass aircraft window, required for photography, was designed for 10,000 hours of life under extreme environments, consisting of high altitude thermal gradients and high pressure differential. Further, the window would need to survive its lifetime in the presence of airborne dust particles at high speed, runway sand and debris, hailstone impact, and frequent handling and cleaning conditions, the latter of which could cause scratches. Analysis showed a lifetime well in excess of 1,000,000 hours, but tests indicated failure times well below 1000 hours. The apparent disconnect was due to the presence of residual stress, heretofore not considered. Additionally, premature hailstone test failure required further assessment to ensure survivability. An extensive redesign resulted in the first ever FAA approval for glass window design in a passenger cabin.

Citation Download Citation

John W. Pepi "Stress failure vignettes: errors of 10,000, the help of Humpty-Dumpty, and others", Proc. SPIE 9197, An Optical Believe It or Not: Key Lessons Learned III, 91970G (13 November 2014); https://doi.org/10.1117/12.2066942

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available