Bending and free vibration response of sandwich laminate under hygrothermal load using improved zigzag theory

Abstract

In this work, the effects of variations in temperature and moisture concentrations on the static and free vibration response of sandwich laminated plates with low-density core have been studied. A higher order zigzag laminate theory is used which satisfies the continuity in transverse shear stress at the layer interfaces and zero transverse shear stress condition at the top and bottom surfaces of the laminate . The displacement field in this theory suitably allows for the quadratic distribution of transverse shear stress across the thickness and transverse compressibility effect of the core. An effective finite element formulation is carried out by employing a nine-node C0 isoparametric element for the above plate model. Numerical examples of composite and sandwich laminates with different material properties, effect of temperature and moisture variation, aspect ratios, boundary conditions, number of layers and ply orientations are considered for the analysis. Efficiency of the present plate model in predicting various responses subjected to hygrothermal loading is verified by comparing with the available published results.