A triangular v. Kármán type finite element for sandwich plates with transversely compressible core Original Research Article

The present study is concerned with a new higher-order finite element for sandwich plates with transversely compressible core. The underlying plate theory is of the multilayer type, where the standard Kirchhoff–Love hypothesis is adopted for the face sheets whereas a second order displacement expansion is used for the core. Geometrical nonlinearities are included in the v. Kármán sense. Based on this plate theory, a triangular finite element with three nodes on each face sheet is developed. The element uses a discrete Kirchhoff approach for the face sheets and a simplified three-dimensional formulation for the core. The discretized nonlinear problem is solved by the Newton–Raphson method. Subsequently, the model is applied to the postbuckling analysis of different sandwich panels. It is observed that the local face wrinkling instability which is enabled by the transverse compressibility of the core has a significant effect on the overall behavior of sandwich plates.