Analytical Solution for the Ultimate Strength of Metal-faced Elastomer-cored Sandwich Panels under In-plane Edge Compression and Lateral Pressure

Abstract

This paper presents a closed-form analytical solution for the ultimate strength of simply supported sandwich panels with metal faces and an elastic isotropic core under combined in-plane compression and lateral pressure. By solving the geometrically nonlinear governing differential equations of imperfect isotropic sandwich panels with a relatively soft core using the ordinary Galerkin method, the stress distribution in the faces under uniaxial and lateral pressure loads is obtained. The ultimate strength equations are then derived on the basis that collapse occurs when yield has spread from the middle of the concave face plate to the mid-length of the unloaded sides of the face plate. The solution is validated by a detailed nonlinear finite element analysis using three alternative models. Because the solution is analytical and closed-form, it is rapid and efficient and is well-suited for use in practical structural design methods, including repetitive use in structural optimization. The solution applies for any elastic isotropic core material, but the application that stimulated the study is an elastomer-cored steel sandwich panel that has excellent energy absorbing and protective properties against fire, collision, ballistic projectiles and explosions.