Geometrically Nonlinear First Ply Failure Loads of Laminated Composite Conoidal Shells

Abstract

Review of the existing literature on shells indicates that first ply failure of laminated conoidal shells, particularly using geometric nonlinearity was not reported by any researcher. Conoidal shell is an aesthetically appealing, stiff, easy to cast surface which is popular to cover large column free open spaces found in shopping malls, auditoriums and aircraft hangers. Lightweight laminated composites are often used to fabricate them. Laminated composite is weak in transverse shear and may initiate failure at any inner lamina. Such latent damages progress gradually within the laminate and lead to sudden catastrophic collapse under service condition. Thus, the first ply failure load has to be known to a practicing engineer. This paper reports first ply failure of conoidal shells using geometrically nonlinear isoparametric finite element formulation. The results are presented for different parametric variations and the study concludes with set of meaningful engineering design guidelines keepingalso the serviceability criterion in mind.