Effects of impactor mass on the low-velocity impact behaviour of thick GFRP pultruded laminates

Abstract

This paper reports on the results of an experimental study on glass fibre reinforced polymer (GFRP) pultruded profiles subjected to low-velocity impact loading. The effects of impactor mass on the impact response of pultruded composites were investigated. Composite specimens were tested under two series of loading conditions using a drop-weight impact facility. The first set of tests was conducted with different impactor masses (i.e. 5.5, 10.5, 15.5 and 20.5 kg) under the same impact energy of 67 J. The specimens in the second set were subjected to varying impactor masses of 6, 12, 24 and 36 kg at the same initial velocity of 4.4 m/s, resulting in different impact energies. The internal and external damage of pultruded composites was analysed to compare the failure mechanisms, including matrix cracking, delamination, and fibre breakage, as functions of the initial impact energy. The results showed that the extent of impact-induced damage increased with ascending impact energies (ascending impactor masses) up to the point at which the specimen was perforated. The initial impact energy was the dominant parameter that controlled the damage tolerance characteristics of pultruded composites. Furthermore, it was found that a significant longitudinal crack was a precursor to ultimate failure.