Study on quasi-static mechanical properties of novel reentrant structures with multiple energy dissipation

Abstract

The protective characteristics of novel bionic structures inspired by turbulent energy dissipation are studied. From the perspective of small-scale turbulent energy dissipation, the reentrant design of structures is carried out, and combined with rotation characteristics of the chiral structure and bending characteristics of the Euler beam, novel bionic reentrant chiral structures with multi-direction torsional energy dissipation characteristics are further designed and constructed: Single Reentrant Chiral Cubic Structure (SRCCS), Double Reentrant Chiral Cubic Structure (DRCCS), Single Reentrant Chiral Honeycomb Structure (SRCHS), Double Reentrant Chiral Honeycomb Structure (DRCHS), Single Reentrant Chiral Negative Poisson Structure (SRCPS), Double Reentrant Chiral Poisson Structure (DRCPS). The relative elastic modulus, yield stress, and plastic failure stress of novel reentrant chiral structures are analyzed theoretically, and the relationship between the relative density and relative elastic modulus, yield stress, and plastic failure stress of novel reentrant chiral structures are compared. The mechanical properties of novel bionic structures in the quasi-static compression process are analyzed from experiments and simulations. The results show that bionic double torsion reentrant structures have the most excellent properties. Energy absorption and load-carrying capacity of novel bionic reentrant structures are 30 % higher than traditional bionic structures. To better determine the excellent performance of the reentrant chiral structures, the reentrant chiral structures are further studied in combination with the crash of the protective helmet of motorcycle racers. It is obvious from the results that the protective effect of helmets with bionic reentrant chiral structures’ sandwich is 25 % higher than the safety helmet with the corrugated sandwich.