The impact and post-impact flexural behaviors of CFRP/aluminum-honeycomb sandwich

This study investigates the medium velocity impact response and post-impact flexural behavior of hybrid sandwich structures. A series of experiments are performed over a range of impact energies to evaluate the effect of structural parameters of sandwich beams on the impact damage and how impact damage affects the residual flexural strength. The experimental results show that the CFRP face sheets play a dominant role in the impact resistance of sandwiches. The impact-induced damage significantly reduces the residual flexural deformation of the sandwiches, as well as their bending strength and stiffness. A theoretical method is proposed to achieve deformation and failure mode prediction of post-impacted CFRP/aluminum-honeycomb sandwich beams. This work provides fundamental understandings on the relationship of pre-impact damages and residual flexural behaviors, so as to guide damage resistant design of composite sandwiches.