A Study on the Influence of Local Buckling on the Strength of Structural Core Sandwich Structures

Abstract

The collapse mechanism of biaxially loaded corrugated board has been experimentally examined. Biaxial loading was accomplished by subjecting board cylinders to axial compression, torque, external pressure and combinations thereof. Failure analysis of the board was based on the stress state in the facings in conjunction with a combined stress failure criterion. The study demonstrates that local buckling is the dominant failure mechanism of the corrugated board when there are large inplane compressive stresses acting in a direction across the corrugations and in the facings. Reduction in strength of the corrugated board due to local buckling was also observed when large shear stresses are present in the facings. In this study we examined the implications of the strength degradation due to local buckling on the performance of various corrugated panels. It is demonstrated that modification of the Tsai-Wu failure criterion to include these failure modes significantly improves the strength prediction of the panels, especially if they are loaded in compression transverse to the corrugations.