Impact Response of FRP Composites Used in Civil Structural Applications

This research aims to investigate the influence of repeated low-velocity impacts on the residual tensile strength of composite laminates reinforced with E-glass/epoxy woven fabrics. To accomplish this, a comprehensive analysis of the specimens was conducted following a series of low-velocity impacts, with each impact delivering a constant energy of 4 J. Several key parameters, including maximum impact load, displacement, contact time, and absorbed energy, were examined. The residual tensile strength of the specimens was evaluated after each impact and subsequently compared to control specimens that had not experienced any impact. The outcomes of this study revealed a noteworthy reduction in the residual tensile strength following the initial impact. As subsequent impacts were applied, their effect on the specimens' tensile strength diminished until the complete puncture of the specimens. The findings of this study demonstrate the crucial role of repeated low-velocity impacts in the degradation of the residual tensile strength of composite laminates. The observed decrease in tensile strength, particularly after the first impact, indicates the vulnerability of these materials to such loading conditions. These findings have significant implications for the design and maintenance of composite civil structures exposed to multiple low-velocity impact events, emphasising the necessity for appropriate reinforcement strategies and monitoring protocols to ensure structural integrity and performance over the intended lifespan of the components.