Enhanced Fracture Resistance Induced by Coupling Multiple Degrees of Freedom in Elastic Wave Metamaterials with Local Resonators

In this study, the dynamic effective parameters and crack arrest behavior of locally resonant metamaterials with multiple degrees of freedom are investigated. Based on the Wiener-Hopf method, the energy release ratio which characterizes the crack splitting resistance is derived, and the influences of the material parameters are discussed. In comparison with the monoatomic lattice chain and locally resonant metamaterials composed of unit cells with a single degree of freedom, this new periodic structure with coupling multiple degrees of freedom displays some essential features during the crack propagation. The results show that due to the coupling of different displacements, the crack dynamic growth in the elastic wave metamaterials exhibit a lower energy release ratio, which indicates a better fracture resistance and arrest property. The present work can be expected to provide a way to improve the ability to resist crack propagation of advanced materials and structures.