A study on the effect of particle shape and fragmentation on the mechanical behavior of granular materials using discrete element method

Abstract

Particle crushing can result in changes in the mechanical properties of granular materials. By using Discrete Element Method (DEM), a model is established to simulate the breakage of two-dimensional particles for three different shapes (triangle, square and hexagon). In the simulations, each particle consists of two sub-particles bonded with each other. Particle crushing will occur during the numerical analysis if the bond between these sub-particles breaks. With this model, the effect of particle breakage on macro mechanical behavior of granular materials can be studied for three particle shapes which have the same equivalent radius. For each of these shapes, two series of biaxial tests, with and without breakable particles, are simulated and the results are compared in terms of shear strength and volume change, then the effect of fragmentation on the global behavior is evaluated for discrepant particle shapes. It is observed that particle breakage has a significant influence on mechanical behavior of granular materials such as a decrease in shear strength as well as volume change; moreover, the particle shape does not have so much effect on the final breakage percentage for this kind of failure.