Effect of hybridization type, hole-distance and number of holes on the resistance of intraply hybrid composite plates against multiple impact

Abstract In this study, the effects of the hole-distance from impact point and numbers of holes on carbon-glass/epoxy composite plates formed by three different intraply hybridizations subjected to repeated (multiple) impact loading with 8 J energy level are examined experimentally. The samples were subjected to multiple impact loading until perforation, which is determined by the impactor moving completely through the samples. The number of repeats for each sample was determined by the impactor perforating the sample. In order to better interpret the effect of the test parameters after of the impact tests, contact force-time and contact force-deflection, contact force-number of repeats and number of repeats-hybridization type change graphs of the samples are given for each hybridization type. Thus, the effects of both hybridization type and number and distance of holes on the repeated impact resistance of carbon-glass/epoxy intraply hybrid composite plates were investigated. Considering all test parameters, the absence of a hole and the hole’s near to the center of the sample significantly affects the sample stiffness, resulting in lower impact resistance. The presence of the hole and its distance from the impact point made the sample more resistant to impact. While the highest number of repeats was obtained for samples no-hole (d0h0), the lowest number of repeats was obtained for samples with four holes at a distance of 10 mm and 20 mm from the impact point. For all three hybridization types, the contact force value gradually decreased as the number of impact repeats of the samples increased. When the change in the damage areas of the samples was examined, the largest damage area occurred in the samples without holes (d0h0). Damage progression generally occurred in the 0° orientation of the lower layer.