Unclassified 



Acrylic plastic 



Plexiglas 



Undersea vehicles 



Design curves 



Habitats 



Viscoelastic 



Submersibles 



0-ring seal 



Finite element 



Pressure cycling 



Deep submergence 



Stress analysis 



Yield failure criterion 



Windows 



Failure theory 



Hydrostatic pressure tests 



Pressure vessels 



Conical viewports 



DD ,T"..1473 B'^cK) 



(PAGE 2) 



Unclassified 



Security Cla 



