Stress Projection, Layerwise-Equivalent, Formulation for Accurate Predictions of Transverse Stresses in Laminated Plates and Shells

A two-phase scheme for accurate predictions of interlaminar stresses in laminated plate and shell structures has been addressed in this study. A modified superconvergent patch recovery (MSPR) technique has been utilized to obtain accurate nodal in-plane stresses which are subsequently used with the thickness integration of the three-dimensional equilibrium equations to evaluate the transverse shear and normal stresses. Remarkably, the continuity of the resulting interlaminar stresses is automatically satisfied. Such a two-phase scheme has been applied successfully to a simple smeared layer model (SLM), i.e., a low-order quadrilateral hybrid/mixed element (HMSH5). This simple procedure is found to be completely equivalent to the far more computationally expensive alternative approaches, e.g., sophisticated layerwise approach, for flat geometry. A fairly large number of numerical examples have been solved and the results have shown that the proposed scheme is fairly reliable and computationally cost effective.