Energy absorption and failure analysis of reinforced hole plate composite materials imitating coconut shell structure

Abstract Over a million years of evolution and natural selection, coconuts have developed remarkable impact resistance and energy absorption capabilities. Based on the bionic structure of the mesocarp fiber distribution of coconut, the compression energy absorption of composite materials under three different distribution modes: vertical distribution, horizontal distribution, and shear random distribution was studied. The materials tested include plate materials with two types of hole characteristics: center holes and offset holes. Additionally, a coupling agent is utilized to modify the fiber, allowing for a comparison of compression energy absorption before and after modification and an analysis of the hole destruction process. Results indicate that the coupling agent significantly enhanced all properties of coir fiber composite materials. Specifically, whether the center hole or the offset hole, the randomly distributed fibers modified by the coupling agent exhibited the most balanced performance. However, due to the relatively high cost of coupling agents, in practical scenarios, horizontally distributed fibers performed best overall without the use of coupling agents. The vertically distributed coupling agent fiber in the central hole exhibits the highest peak load and equivalent yield limit, making it suitable for high‐stress environments. Furthermore, the random distribution of coupling agent modification remains the most balanced. In the offset holes, the randomly distributed fibers with coupling agent modification are only inferior in resisting lateral displacement compared to the laterally and vertically distributed coupling agent modifications, while excelling in all other properties. Highlights Compression energy absorption of composites with various arrangements of fibers Compression energy absorption of composite with different positions of the hole. Compression energy absorption under different treatment methods of fibers. Scanning electron microscopy was conducted to verify the results.