First ply failure analysis of laminated panels under transverse loading

The present investigation deals with the failure analysis of the weakest ply in a laminated composite plate or shell using the method of finite elements. The objective of the s tudy is to detect the stress level at the stage of initiation of damage in the composite panels. An eight noded isoparametric quadratic shell element has been used applying first order shear deformation theory. The elegance of the present formulation lies in the capability of analysing plate as well as shallow and deep shell using a s ingle formulation. Various failure criteria have been studied to predict the load when the weakest lamina fails under transverse static load. The investigation has been made on various plates and shells having varying lamination schemes. Published results on first ply failure analysis of laminated plates are scanty, however the results on laminated shells are not available in the literature. A number of problems on laminated plates have been solved and the results are compared with those available i n the relevant literature. A parametric study has been carried out in the present investigation to predict the failure load of laminated shells.