High‐Order Buckling Analysis of Sandwich Beams with Transversely Flexible Core

Abstract

Buckling behavior of sandwich beams with a soft core is presented. The buckling analysis consists of formulation of linear and nonlinear behavior equations, boundary conditions, and continuity conditions. The beam construction is general and consists of two skins (not necessarily identical), metallic or composite laminated symmetric, and a soft core made of foam or a low‐strength honeycomb that is flexible in the vertical direction. The analysis uses a high‐order theory that permits nonlinear distortion of the plane of section of the core as well as changes in its height. Closed‐form solutions are presented for simply supported beams with identical skins and only numerical results for other cases. The analysis determines overall and local buckling behaviors as well as deformations, internal resultants, and stresses in the interface layers between core and skins due to imperfections. Numerical studies reveal that under some structural configurations, local buckling is critical, rather than global buckling. The imperfection analysis study explains the sensitivity of such structures to premature failure due to disbonding of one of the skins from the core.