Study on the Low‐Velocity Impact Damage Characteristics and Mechanism of Composite Laminates

ABSTRACT To investigate the damage characteristics and mechanisms of composite‐material hull plates under low‐velocity impacts, low‐velocity impact tests were conducted on clamped glass–fiber‐reinforced composite plates. The damage modes, damage thresholds, and dynamic response processes of the clamped fiber‐reinforced composite materials were analyzed through dynamic strain measurements, backlighting damage observations, and finite element numerical simulations. The results showed that under low‐velocity impacts from flat‐ended impactors, the damage of the clamped laminated plates was mainly characterized by matrix damage and delamination damage at the center and boundaries. In the central region, ring‐shaped or elliptical ring‐shaped damage formed due to the out‐of‐plane shear force and bending action at the edge of the impactor head. In the boundary region, strip‐shaped damage, dominated by interlaminar shear forces, appeared first at the midpoint of the longer side. Laminate optimization had a significant effect on damage suppression. A rational 45° stacking sequence could enhance the resistance to delamination and reduce the damage area. Moreover, thicker laminated plates exhibited higher energy absorption capacities under higher energy impact levels, but the damage area could experience a sudden increase in size at specific energy levels.