Core and face sheet anisotropy in deformation and buckling of sandwich panels

The present study is concerned with an analysis of anisotropy effects on the deformation and instability behavior of structural sandwich panels with laminated face sheets and orthotropic, transversely compressible core. Both, the overall buckling and the local face wrinkling instability modes are addressed in a coupled analysis using a nonlinear, higher-order sandwich shell model. It is observed that the global and local instabilities are coupled rather than independent features. Furthermore, the local face wrinkling instability might have a considerable effect on the global deformation behavior of the structure in the (global) pre-buckling range. Both the stacking sequence of the face sheets and the orthotropicity ratio of the core are found to have a significant effect on the occurrence of the different instability modes.