Similitude of sandwich panels with a ‘soft’ core in buckling

The paper presents the similarity analysis of a sandwich unidirectional panel with a transversely flexible core under buckling loads. The governing equations are those used in the high-order analysis of sandwich panels with a ‘soft’ core. The study derives the similitude conditions in the case of external in-plane compressive loads that yield buckling of the panel with and without imperfections. In the first part, the buckling analysis is presented and it is based on the linearized version of the governing equations of the non-linear geometrical bending equations. The presentation includes an analytical proof of the applicability of similarity for the buckling of a sandwich panel with identical faces and a numerical demonstration of the response when full similarity and partial similarity exist. The effects of full and partial similarity are presented for a panel with imperfections.