Elastic-Plastic Wrinkling of Sandwich Panels With Layered Cores

Abstract

Elastic-plastic wrinkling of compression loaded sandwich panels made with layered cores was studied analytically and experimentally. A core with a stiff layer near the sandwich skins can improve various properties, including wrinkling and impact strengths, with only a minor weight penalty. The 2D plane stress and plane strain bifurcation problems were solved analytically, save for a determinantal equation which was solved numerically. Experiments were performed on aluminum skin/foam core sandwich panels with different combinations of stiff and soft core materials. Good correlation between experiments and theory was obtained.