With the emergence and development of meta-structures

many phenomena in the field of mechanics that are difficult to realize with conventional materials or structures are gradually becoming possible. Fibre reinforced composites have excellent mechanical properties and can meet the requirements of light weight and high strength. Combining the performance advantages of advanced fiber composites and the unconventional behavior of auxetic metastructures

a negative Poisson’s ratio meta-structure (also called auxetic meta-structure) was prepared by hot pressing molding through a combination mould based on carbon fiber reinforced epoxy resin composite and the classical re-entrant configuration. Subsequently

studies on deformation

failure

buffering and energy absorption of the auxetic meta-structures were carried out by quasi-static and dynamic impact experiments

and the corresponding finite element analyses were also performed. The results show that the meta-structures have different load-bearing capacities

failure modes and auxetic effects in different characteristic directions (including re-entrant direction #1

vertical to the re-entrant direction #2 and outof-plane normal direction #3). Specifically

there is an auxetic effect when the impact is in the #2 direction and the failure mode is wrinkle fracture

whereas when the impact is in the #3 direction

there is no progressive failure but rather buckling separation from the bond interface. The failure modes of auxetic meta-structures have been shifted compared to the quasistatic case

therefore

impact energy absorption

specific energy absorption and auxetic effect are weakened. In the future

triggering methods and filler materials can be further developed to improve the buffering and energy absorption of the auxetic meta-structures

so that they can be applied in the field of impact protection engineering.