Numerical investigation on composite laminates under double-position low-velocity impacts

The dynamic mechanical behaviors of the [ 0 2 ° / 90 2 ° ] 4 s fiber-reinforced composite laminates subjected to double-position low-velocity impacts are investigated by finite element method. Two impact positions symmetrical about the center of the laminates are impacted sequentially with three impact distances (10 mm, 20 mm, and 40 mm) under three impact energies (5 J, 10 J, and 20 J) to study the interference effect of impact damage. For comparison, plastic damage model (PDM) and elastic damage model (EDM) are established to describe the intra-laminar constitutive, respectively. Compared with available experimental data, the mechanical responses calculated by PDM are more accurate, especially at high energies. Affected by the impact interference, the oscillation of force-time curve for the second impact rather than the first impact is relatively weaker, while the severity of impact damage is reversed. The results show that the maximum displacement is more suitable for characterizing the degree of damage interference than bending stiffness, peak force, and energy dissipation.