Preliminary study on the effect of microstructure shape on impact compression dynamic fracture of two-dimensional brittle materials protective structures

Abstract

Under the shock wave compression, the common cracks will rapidly expand and penetrate, resulting in a catastrophic fracture phenomenon, which can seriously threaten the structural design function of brittle material samples and limit their practical application range. By introducing and designing protective structures containing microstructures, the plasticity of the sample against impact can be significantly increased, effectively avoiding or slowing down the onset of failure. A lattice-spring model suitable for demonstrating the elastic properties and fracture simulation of brittle materials is used in this paper to investigate the effect of the shape of the microstructure on its impact properties. The calculation results show that the shape of the microstructure will affect the evolution characteristics and laws of the shock wave profile. Compared with the stress curves, it can be found that the microstructure with negative Poisson's ratio has greater impact plasticity. The analysis of the mesoscopic deformation characteristics of different microstructure shapes shows that the penetration and volume shrinkage deformation of the concave hexagon, the concave triangle and the fourth-order star-shaped microstructure are dominant, and the strain localization is significant. The research results of the microstructure, with negative Poisson's ratio properties, that can significantly enhance the macroscopic impact plasticity of brittle materials will help to improve their prevention in terms of impact failure and provide guidance for the optimal design of protective structures. The findings that microstructures with negative Poisson's ratio properties can significantly enhance the macroscopic impact plasticity of brittle materials, as revealed in this paper, will help to improve their prevention in terms of impact failure and provide guidance for the optimal design of protective structures.