Research on low-velocity impact damage and influencing factors of composite laminates

To explore the damage behavior of composite laminate panels under low-velocity impact loading, an investigation of the impact performance of composite material plates under low-velocity impact loading was conducted through drop hammer impact tests. A unified theoretical framework regarding intra-layer damage and interlayer delamination in composite laminates was proposed. An enhanced strain-based Hashin criterion was implemented through the Abaqus/Explicit User Material Subroutine (VUMAT) to model intra-layer damage, while a modified traction-separation law, accounting for strain rate effects, along with the B-K criterion, were employed to simulate interlayer damage. A detailed low-velocity impact model was developed, and the simulation results exhibited strong agreement with experimental data. A novel approach incorporating strain rate effects is proposed. The damage characteristics of low-velocity impact were systematically analyzed, and the effects of impact energy, impactor radius, and impact angle on the low-velocity impact damage characteristics of laminate panels were examined. The results revealed that the predominant damage modes in composite laminate panels under low-velocity impact were matrix cracking and delamination. Impact energy and impact angle significantly influenced low-velocity impact, with the damage degree increasing as impact energy increases and decreasing as impact angle increases. In contrast, the effect of impactor radius was negligible. The proposed high-precision modeling approach could effectively predict the evolution of low-velocity impact behavior.