New 3D petal-like structures with lightweight, high strength, high energy absorption, and auxetic characteristics

A novel type of petal-like structure that exhibits superior mechanical properties, was proposed and fabricated by integrating advantages of metamaterial, multi-stage deformation, and high strength of fiber-reinforced composites. Compression testing and finite element analysis were first conducted on three petal-like structures formed with different angles and made from fiber-reinforced composites. The findings indicated that these composite-based multi-cell structures can also exhibit a satisfactory stress plateau stage through judicious structural design. After ensuring the structures' performance under quasi-static compression load, the impact resistance of the new structures was further examined. It was found that the structure's auxetic characteristics diminished under low-speed impact load. However, under a 20 J impact load, the structures exhibited energy absorption characteristics (SEA) that surpassed those of both conventional and other new auxetic structures by 8–40 times. These promising results demonstrate that the newly designed petal-like structures have high potential applications in various fields such as construction and automotive industries.