Discrete-element method investigation of the resilient behavior of granular materials

This paper presents the results of numerical simulations of the resilient modulus test used to mechanically characterize the resilient behavior of aggregate materials, commonly used in pavement bases and subbases. The investigation made use of the discrete-element method (DEM) to replicate the particle behavior usually experienced during laboratory sample preparation and testing. The simulations were based on assemblies of circular particles confined between top and bottom rigid boundaries and laterally confined at constant stress. Contact forces and displacements were assumed to obey a linear relationship and shear forces were bounded by a maximum value (Coulomb friction law). Compacted samples were subjected to deviator repeated loads. The investigation showed that the DEM is capable of reproducing the results of the resilient modulus test performed on real granular materials in a qualitative manner. Further, the method predicted the effect of the state of stress depicted by laboratory testing.