Progressive Damage Modeling of Sandwich Composites under Edgewise Compression

Composite sandwich structures offer several advantages over conventional structural materials such as lightweight, high bending and torsional stiffness, superior thermal insulation and excellent acoustic damping. Failure in sandwich structures can occur in the form of core crushing and shear, facesheet failure and delamination. Numerical simulation is a valuable tool by which the mechanical behavior of sandwich composites can be estimated in a cost-effective manner. In the current work, a three dimensional nonlinear finite element model was built to describe sandwich composite behavior under edgewise compression. Hashin's failure criteria was used to model facesheet failure and a cohesive zone model was used to predict delamination at the core-facesheet interface. Sandwich composites were manufactured using carbon/epoxy prepregs and aluminum honeycomb, to validate predictions of the numerical model. Load carrying capacity predicted by the numerical simulation was found to be in good agreement with experimental findings. Such numerical models can be used for design purposes to determine the influence of sandwich components on the behavior of the sandwich structure.