On low-velocity impact behavior of flexible and stiff composites for better energy absorption

Abstract

This research investigates the low-velocity impact behavior of two distinct jute-based composite configurations: flexible composites comprising jute fibers embedded in a rubber matrix and stiff composites consisting of jute fibers embedded in an epoxy matrix. The primary objective is to evaluate their respective energy absorption capabilities under controlled impact loading conditions, with implications for enhancing impact resistance across diverse industrial domains. Mechanisms governing damage in these composite systems are thoroughly examined. Using a specialized testing apparatus, drop weight impact experiments were performed to evaluate the composites’ low-velocity impact response, with an emphasis on how much energy is absorbed and the related damage techniques. Flexible composite with jute/rubber/jute/rubber/jute (JRJRJ) absorbs 15.5% more energy compared to stiff epoxy-based composite with 10 layers of jute (JE10). Jute/rubber/jute (JRJ) exhibits energy absorption of 70.24% more, compared stiff epoxy-based composite with 7 layers of jute (JE7), and jute/rubber/rubber/jute (JRRJ) exhibits 53.44% more energy compared to stiff epoxy-based composite with 9 layers of jute (JE9). The findings indicate that flexible composites, benefiting from the elastomeric properties of the rubber matrix, exhibit superior energy absorption capabilities compared to their stiff counterparts. The inherent flexibility of the rubber matrix facilitates greater deformation upon impact, leading to prolonged impact duration and improved energy dissipation. In contrast, stiff composites demonstrate higher initial stiffness but limited energy absorption capacity due to their inherent rigidity. Detailed damage analysis sheds light on the distinct failure mechanisms within the composite structures. While compliant composites predominantly experience matrix tearing upon failure, stiff composites exhibit matrix cracking, suggesting a more catastrophic failure mode. This suggests that there is a lower risk of a catastrophic breakdown with the suggested compliant materials, rendering them particularly suitable for low-velocity impact applications where controlled energy absorption and damage mitigation are critical considerations.