Investigation on impact damage and residual in-plane compression strength of FML laminates

Fiber metal laminates (FML) have attracted considerable attention due to their excellent attributes of light weight, high strength, ease of shaping. This work focuses on investigating the impact responses and residual in-plane compression strength of two distinct FML configurations, namely, FRP-Alloy-FRP (FAF) and Alloy-FRP-Alloy (AFA). The impact experiments have unveiled notable differences in terms of dynamic deformation and internal debonding within FMLs. Notably, FAF laminates display less than one-third of the post-impact residual deformation in comparison to AFA specimens of equivalent mass. Moreover, the compressive tests indicate that AFA laminates retain a considerably higher compression after impact (CAI) strength compared to FAF and CFRP specimens. This discrepancy can be attributed to variations in out-of-plane stiffness, interfacial debonding, and out-of-plane deformation among the different components. Additionally, numerical simulations have provided insights into the influence of aluminum alloy plate thickness and impact velocity on the failure mode.