Saint venant's principle in sandwich strip

Abstract

The Saint Venant's principle is generally accepted to be valid in most problems in structural mechanics. But some earlier studies have drawn attention to the fact that routine application of Saint Venant's principle in the solution of elasticity problems of sandwich type structures is not justified in general. The aim of the investigation reported herein is to study the applicability of Saint Venant's principle to the problem of a sandwich strip quantitatively in detail. A simple finite element model, with linear strain triangles representing the core and bar elements representing the thin faces, is used for the analysis. Four different load cases are studied, and representative numerical results are presented. In all cases it is observed that significant edge disturbances do exist at relatively large distances from the load point, compared to homogeneous type of construction. Strength of Materials solutions are valid only beyond a distance of “4h” from the loaded end in the case of very soft cores, the distance being less for more rigid cores. Also very high values of face to core modulus ratio do not influence the solution significantly.