Modulus of Core Reaction Approach To Buckling of Sandwich Plates

This paper deals with the linear stability analysis of sandwich plates modeled as thin plates resting on elastic media. To compute the elastic buckling coefficient of sandwich plates, equations have been presented in the literature by using a coefficient R, which relates the rigidity of facing to the core. In the finite element analysis, if the sandwich plates are to be modeled as plates supported by Winkler elastic springs, the relative rigidity R cannot be directly used to represent the stiffness of the Winkler springs. Instead, the stiffness of the core has to be expressed as a modulus of subgrade/core reaction. Furthermore, the R value cannot be directly used in a finite element postbuckling analysis of sandwich plates. In this study, an empirical relation between modulus of core reaction and the R value is established. This is then used in the finite element computation of buckling loads of sandwich panels. This modulus of core reaction can be directly used in the linear buckling analysis of sandwich plates as well as the postbuckling analysis using finite elements.