Stress concentration and local behaviour of prestressed composite laminates/sandwich plates with overhangs in cylindrical bending

摘要

A displacement-based elastic solution for local load problems of composite laminates/sandwich plates with special attention on quantifying local stress fields of critical zones is presented. The laminates are considered as cross-ply/angle-ply multilayer plates with overhangs in cylindrical bending caused by transversely concentrated line-load and in-plane uniform load. The detailed description of the local behaviour of laminates/sandwiches is obtained by depicting normal and shear stress components in terms of the load intensity. The high sress gradient, which could not be measured by experimental means, is determined around the load area and sharply supported regions. The effect of the edge (in-plane/out-of-plane) pre-restraint to the local behaviour of laminates/sandwiches is examined by performing a parameter study, of which the issue of changing materials and the laminate's configuration is also discussed. The results reveal interesting rnechanical features which are essential to understanding the failure phenomena of such laminates subjected to the concentrated loads. To get the reference data, a FEM mesh corresponding to the analysis model is generated by using plane-strain continuity elements. The corresponding numerical results are assessed on the displacement and stress fields over the whole investigated region.