Comparative numerical study on the impact resistance of Z‐pin reinforced and unreinforced composite laminates

Abstract Compared with the common numerical analysis of out‐of‐plane low‐velocity impact (LVI) of composite laminates, this paper established a finite element model (FEM) for out‐of‐plane LVI of unreinforced laminates and Z‐pin‐reinforced laminates. The mechanical response and damage morphology of the model after impact at energies of 5, 10, 30, and 50 J were verified with experiments. Through mechanical response research, it was found that the numerical analysis models of LVI of unreinforced and Z‐pin‐reinforced laminates have higher prediction accuracy for maximum impact force, maximum displacement, and energy absorption of the laminate. The simulation results showed that the Z‐pin reinforced laminates had higher impact force and lower maximum displacement compared to the unreinforced laminates. From the LVI simulation, it was observed that the damage morphology of the laminate's surface and interior indicated minor fiber damage, which correlated well with the fiber damage observed in the experiments. In contrast, matrix damage played a dominant role during the impact, leading to extensive damage. This extensive damage occurred due to the loss of the stress transfer medium caused by matrix damage, which subsequently resulted in fiber damage. Highlights Comparison of simulated and experimental mechanical response Criteria for determining the initiation of matrix/fiber damage Simulation analysis of Z‐pin reinforced laminates Intra‐laminar fiber/matrix damage and inter‐laminar delamination