First ply failure study of thin composite conoidal shells subjected to uniformly distributed load

• The cross ply laminates yield higher failure loads than angle ply ones.
• The conoidal shells fail or tend to fail by inplane shear at the bottommost lamina.
• Fibers in bottommost lamina should be oriented along arch direction of the shell.
• The cross ply unit (0°/90°) should not be repeated more than twice in the laminate.

The civil engineers often need to cover large column free open spaces with thin shell structures. The doubly curved shells are characteristically stiff and the ruled surfaces are easy to fabricate. The aesthetically pleasing conoidal shells satisfy both these criteria and are preferred by structural engineers. The engineers now look out for strong but lightweight materials and as a result the laminated composites have evolved. The first ply failure is very important issue for laminated composites. Such studies for plates are reported but similar work on thin shells is very scanty. This paper is aimed to fulfill this lacuna.