Semi-energy finite strip post-buckling analysis of laminated plates concerning the effects of mechanical coupling

In composite laminated plates the mechanical coupling is one of the significant properties which dominate the performance of a laminated plate structure in large out-of-plane deformations. Some effects of mechanical coupling on the post-buckling behavior of composite laminated plates have been studied in this paper by implementing a finite strip approach based on the concept of a rigorous post-buckling solution for composite plates and plate structures, namely the semi-energy approach, which has been originally developed by the authors of current paper. Moreover, to check the validity and soundness of presented semi-energy FSM the results obtained from developed approach are compared with those obtained from a fairly conventional and well exploited finite strip technique, namely the full-energy finite strip method as well as the obtained results from ANSYS (i.e. the general purpose finite element method software). In this paper, the post-buckling behavior of an anti-symmetric angle-ply square plate with the stacking sequence configuration as [±45]2 has been studied. Moreover, according to anti-symmetric nature of lamination in the mentioned plate there exists a mechanical coupling between in-plane membrane and out-of-plane twisting curvature; therefore, the results of this analysis have been referred as coupled solution in this paper. In order to evaluate the effects of mechanical coupling on the post-buckling performance of mentioned plates, the uncoupled solution has also been determined by precluding the coupling terms (i.e. B16, B26). The post-buckling load–end shortening and load-maximum out-of-plane deflection paths have been obtained for coupled as well as uncoupled solutions. The comparison between the obtained results by coupled and uncoupled solutions revealed markedly different behaviors due to presence of mechanical coupling in the anti-symmetric angle-ply laminates. The outcome of the paper can help structural designers have a better understanding of the effects of mechanical coupling on the post-buckling behavior of laminated composite plates at the design stage.