Experimental investigation of dynamic behaviors and energy absorption of novel personal protective composites under repeated impacts

Explosion accident posing severe threats to human. Current research primarily focuses on engineering protective materials, with limited attention to those for human protection. In this study, personal protective composites with a unique structure were developed by incorporating carbon fiber laminates, artificial cartilage foam, and metallic springs. Considering that foamed material plays a major role in resisting impact, the knowledge of its repeated impacts becomes a key design parameter to ensure impact resistance and long-term stability of the structure. In view of this, the present work investigated the dynamic behaviors and energy absorption mechanisms of composites under repeated impacts, considering the effects of composite structure, including wire and external diameters, and providing a meaningful comparison with traditional protective materials. The results showed that designed composites demonstrated superior impact resistance and durability. Increasing the wire diameter of the composites reduced deformation, with energy being dissipated through material failure, leading to fewer impact cycles. Increasing the external diameter of the composites effectively enhanced their specific energy absorption. Moreover, the changes in the pulse signal during the Split-Hopkinson Pressure Bar (SHPB) test were found to characterize the internal destruction and damage accumulation within the composites during repeated impact. The results showed the rate of peak reflected strain change gradually increased as impact damage accumulation. These findings provide both a theoretical basis and experimental support for the design and durability evaluation of personal protective composites.