High-velocity impact resistance of stepwise gradient sandwich beams with metal foam cores

Abstract

This paper aims to reveal the impact resistance of the graded sandwich beams subjected to high-velocity impacts experimentally. By using the one-stage gas gun system, the dynamic response and failure of the sandwich beams are analyzed by considering the effects of core gradient, impulsive loading, and boundary condition. The results show that the dynamic structural response of beams is noticeably influenced by the different initial failure mode under the fully clamped condition. The core gradient configuration is confirmed to have no significant effect on the impact resistance performance in terms of the dynamic central deflection, permanent deformation, and failure modes. Under the simply clamped condition, however, the core gradient effect is confirmed to be the predominant factor for the noticeably changed impact resistance performances of the sandwich beams. Due to the advantages on structural response and core compression, the graded sandwich beams have significantly better impact resistance than the uniform sandwich beam under the low-velocity impact. The negative correlation between this advantage and impulsive intensity indicates that impact resistance of the uniform sandwich beam is superior to that of the graded sandwich beams under the intensive impact. This study provides guidance of the gradient designation of the energy absorption sandwich structure and its subsequent engineering applications.