Comparison of stacking sequence on the low-velocity impact failure mechanisms and energy dissipation characteristics of CFRP/Al hybrid laminates

Abstract

Compared with the resin-based composite laminates, fiber metal laminates (FMLs) have superior impact resistance. In this study, investigations were made to reveal the effects of stacking sequence on the low-velocity failure mechanisms and energy dissipation characteristics of carbon fiber reinforced plastics (CFRP)/Al hybrid laminates with same areal density. Experiments were carried out to characterize the typical mechanical responses. Failure morphologies were evaluated by X-ray computed tomography scanning techniques. Then numerical simulations based on three-dimensional progressive damage analysis were applied to reveal the dynamic evolution process and energy dissipation characteristics. Results indicated that plastic deformation of aluminum layers acted as the dominant factor in energy dissipation. Stacking aluminum layers on the exterior surface could increase the absorbed impact energy and reduce the fracture behavior of the component layers. The specimens with more CFRP layers stacked on the surface exhibited more severe fracture behavior of component layers and larger delamination areas, thus promoting the energy dissipated by CFRP cracking and delamination. This work intended to provide practical guidance for the structural design of fiber reinforced polymer/metal hybrid protective structures.