Finite element prediction of first-ply failure loads of composite thin skewed hypar shells using nonlinear strains

Abstract

The application of skewed hypar shell as civil engineering roofing unit is an established fact. Such use has gained a greater momentum when this shell is fabricated with advanced materials like the laminated composites. Research attempts in studying the first ply failure behaviour of laminated composite structural units are common now among engineers and the novelty of this paper lies in continuation of such efforts being applied to composite skew hypar shell. For accurate modelling of the failure behaviour of this thin shell, nonlinear strains are considered together with eight noded isoparametric serendipity finite element. Different well-established failure criteria including the failure criterion of Puck are used to extract the first ply failure pressure values, failure locations and failure modes as well. The finite element code developed is used for numerical experimentation with parametric variations and the results are post processed and interpreted to extract meaningful engineering conclusions.