Damage sustained by a carbon/ epoxy composite material subjected to repeated impact

Effect of repeated impacts on the response of plain-woven hybrid composites

“…4a, which represents the contact force history of the 1st impact, has two peaks. As reported by many studies previously (e.g., Wyrick and Adams [6,25], and Liu and Liaw [24]), the sudden drop in contact force right after the first peak, which was around 7 kN in this curve, indicates the occurrence of damage (in the forms of delamination and/or cracking, which are shown as the circular-and cross-shaped damages in Fig. 3, respectively).…”

“…4a-c, the peak force sustained by the composite increased initially until the maximum peak force was reached. This phenomenon has been reported by other researchers as well [6,7,17,24] can be exemplified by two reasons. First, Wyrick and Adams [6,25] suggested the initial increase in the peak force resulting from the compaction process of the thin layer of unreinforced resin at the impacted surface.…”

“…Then individual fibers, which failed mainly due to transverse compression fatigue, were cracked and removed from the surface, and pits (i.e., erosion) developed. Wyrick and Adams [6] studied damage sustained by 16-ply quasiisotropic carbon/epoxy composite laminates subjected to repeated impact at various energy levels. Impact energy level and number of impacts were found to be major factors influencing damage.…”

Influence of multi-impacts on GFRP composites laminates

“…However, under repeated impacts the laminates experienced a large deterioration in flexural strength because of fracture of the glass fibres [17]. Wyrick and Adams [18] observed that damage in the carbon/epoxy laminates increased with increasing number of impacts of the same energy. The main damage occurs during the first impact and, after, each impact promotes little incremental damages [18].…”

“…Wyrick and Adams [18] observed that damage in the carbon/epoxy laminates increased with increasing number of impacts of the same energy. The main damage occurs during the first impact and, after, each impact promotes little incremental damages [18]. On the other hand, Ho et al [19] shows that the fibre pullout and fibre breakage are the major fracture mechanisms in repeated impacts for polycarbonate composites.…”