A comparison of structural collapse of fully clamped and simply supported hybrid composite sandwich beams with geometrically asymmetric face sheets

This paper focuses on structural collapse of fully clamped and simply supported hybrid sandwich beams of geometrically asymmetric carbon fiber-reinforced composite face sheets and an aluminum foam core under three-point bending. Both bending behavior and collapse mechanism have been explored and identified through the collapse mechanism map. Limit analyses have been conducted and these predictions are validated by experimental results. Experimental results show two active failure modes: face fracture and core shear. Effect of fully clamped boundary condition is to make bending deformation mechanism towards stretching of face sheets and core and strengthen the structural load-carrying capacity. Geometric parameters have significant influence on the initial failure load of hybrid sandwich beams under different boundary conditions. The initial failure modes are significantly affected by the mass distributions of face sheets with the same core thickness. The fully clamped sandwich beams with thick front face sheet have better fracture-resistance. For the similar failure modes, the load-carrying capacity of the simply supported sandwich beam with thick front face sheet is higher than that with thin front face sheet. The initial failure load of face fracture increases with increasing the front face sheet thickness and the initial failure load of core shear increases with increasing the core thickness.