Influence of the distance between projectiles in simultaneous multiple impacts on <scp>CFRP</scp> laminates

Abstract Composite structures in the aerospace and railway industries frequently experience single or multiple low‐ or high‐velocity impacts. The dynamic behavior of composite structures under single impacts cannot be extrapolated to multiple impacts. This study investigates the influence of the distance between projectiles in simultaneous multiple impact scenarios using a finite element model for multiple impacts on carbon fiber‐reinforced polymer (CFRP) laminate plates. The critical distance between projectiles, where stress wave interaction becomes significant, was identified. Results indicate that a distance between the centres of the projectiles of approximately two to three times the projectile diameter is the most damaging for simultaneous multiple impacts. Highlights A finite element model for multiple impacts on CFRP laminate plates was developed. Four different distances between projectiles were evaluated. The ballistic limit, out‐of‐plane displacements, energy absorption, and related parameters were studied. A distance of twice the projectile diameter was identified as the most critical. The distance between projectiles significantly affects the synergistic effects.