Dynamic Response and Damage Accumulation of Laminated Composites under Repeated Low-Velocity Impacts

• Published in: Materials Vol. 16; no. 2; p. 778
• Main Authors: Sun, Jin, Huang, Linhai, Dai, Yunfeng
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 12-01-2023; MDPI
• Subjects: Carbon fibers; Communication; composite laminates; Damage accumulation; Damage tolerance; Dynamic response; Energy; Energy absorption; Fiber composites; Graphite; Impact damage; Impact resistance; Impact tests; Laminar composites; Laminates; Mechanical analysis; mechanical response; repeated impacts; Stiffness; Velocity; damage accumulation; composite laminates; repeated impacts; mechanical response
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma16020778

The mechanical response and damage accumulation of carbon-fiber-reinforced composite laminates subjected to repeated low-velocity impacts were experimentally investigated. The repeated impact tests were conducted on [90
/-45
/0
/45
]
quasi-isotropic and [90
/0
]
cross-ply composite laminates under 16.8 J impact energy, respectively. For each impact, impact responses such as force-time, force-displacement and energy-time curves were recorded. The trends of peak force, maximum central displacement, energy absorption rate and bending stiffness with the increasing impact number were summarized, and the maximum number of repeated impacts corresponded to the occurrence of penetration events. The results showed that the delamination initiation, fiber breakage and penetration were the three typical characteristics describing the damage evolution of the repeated impacts. The damage accumulation of both the laminates was characterized by employing appropriate damage indices. By contrast, the quasi-isotropic laminates had higher impact resistance and damage tolerance, and their damage accumulation was relatively slower.