Hierarchical negative stiffness mechanical metamaterials

Negative stiffness mechanical metamaterials (NSMMs) have enormous application potential in fields such as energy absorption due to their unique mechanical properties. Currently, a large number of NSMMs with novel configurations have been proposed, greatly enriching the concept of such structural materials. However, the hierarchical structural design approach, commonly used in periodic structures, has not been applied in the design of NSMMs. This study proposes a new type of NSMM with hierarchical structural characteristics. Through experiments and numerical simulations, the mechanical properties and energy absorption performance of this hierarchical negative stiffness metamaterial were studied. The effects of structural parameters on the performance characteristics were analyzed, and a comparison was made between this hierarchical structure and traditional structures. The study shows that the hierarchical design can effectively optimize the mechanical response curve of NSMMs, constructing a flatter stress platform, which promotes the enhancement of energy absorption performance for such structures.