Vibration frequencies of simply supported polygonal sandwich plates via Kirchhoff solutions

This study is concerned with the free vibration of general polygonal sandwich plates based on the Reissner-Mindlin shear deformation plate theory. The polygonal plate considered is simply supported on all its straight edges. It will be shown herein that the vibration frequencies of such sandwich plates may be computed from their well-known Kirchhoff plate counterparts via an exact relationship. This exact relationship should be useful for the development of approximate vibration formulae for sandwich plates of other shapes, boundary and loading conditions and may also serve in checking vibration frequencies computed from shear deformable plate analysis software