An improved C0 FE model for the analysis of laminated sandwich plate with soft core

An improved C0 two dimensional finite element model based on higher order zigzag plate theory (HOZT) is developed and applied to the analysis of laminated composite and sandwich plates under different situations to study the performance of the model. In the proposed model, the in-plane displacements variation is considered to be cubic for both the face sheets and the core, while the transverse displacement is assumed to vary quadratically within the core and remains constant in the faces beyond the core. It satisfies the conditions of transverse shear stress continuity at the layer interfaces as well as satisfies the zero transverse shear stress condition at the top and bottom of the plate. The well-known problem of continuity requirement of the derivatives of transverse displacements is overcome by choosing the nodal field variables in an efficient manner. A nine-node C0 quadratic plate finite element is implemented to model the HOZT for the present analysis. Numerical examples covering different features of laminated composite and sandwich plates are presented to illustrate the accuracy of the present model.