Peridynamics simulation for dynamic response of granular materials under impact loading

The dynamic mechanical behavior of granular materials under impact load is a complex issue. Peridynamics as a new theory based on discontinuous and nonlocal hypothesis regards materials as compositions of massive material points with finite volume and finite mass, and builds an integral governing equation to reflect the motion law of material points. For all the features mentioned above, peridynamics is certainly suitable for describing and analyzing the dynamic behavior of particles. An improved PMB model considering the feature of nonlocal long range force and eliminating the “boundary effect” and a repulsive force model at material point level to describe the inter-particle contact interaction are proposed. Then the method is applied to analyze the dynamics responses of tungsten carbide (WC) ceramic granular system suffering from impact loading. Wave velocities of the system were calculated accurately under different impact velocities compared with the experiment results. Phenomena of the motion, including translation and rotation, deformation and crushing of particles are reappeared. There are both total damaged particle and slight damaged particle near the impactor, and there are also particles far out from the impactor which are damaged. The extrusion, collision and shear slide between particles result in the particle crushing. The results indicate that the calculation model and analysis method developed here can well reflect the dynamic behavior of granular materials and have large application value. © 2016, Editorial Office of Chinese Journal of Theoretical and Applied Mechanics. All right reserved.