Experimental Investigation on Impact Behaviors of Thermoplastic Polyurethane Composites

This study presents an experimental investigation into the low-velocity impact behaviors of Kevlar/thermoplastic polyurethane (TPU) composite laminates. Using a drop-weight impact apparatus, composite laminates with three different matrix volume fractions were subjected to impact energies ranging from 10 J to 50 J. A high-speed camera has been utilized to capture dynamic deformation morphology. The impact behavior of TPU composite is featured by smooth mechanical response histories with the absence of severe failure or fiber breakage, even at high energy level. Findings also reveal that increasing TPU matrix content can enhance the laminate impact stiffness, which is coherent with elevated peak force and reduced deformation. Notably, deformation morphology characterizes recoverable wrinkles on the rear-side surface underscoring the enhanced damage tolerance of laminates due to the large deformation. The findings are significant for the design of safer, more resilient composite structures, highlighting the potential application of TPU-based laminates in the fields.