Parameter sensitivity in DEM of aggregates for road and construction materials

• Parameter sensitivity governing the angle of repose of road aggregates is quantified. • Angle of repose test models are constructed using the discrete element method. • Different contact models are compared for predicting aggregate angle of repose. • The influence of aggregate shape on parameter sensitivities is considered. The discrete element method (DEM) is widely used in civil engineering and road engineering to simulate the motion and interaction of aggregate particles in pavement structures. Due to the interaction between particles, selecting or calibrating particle property input parameters is one of the critical issues in DEM implementation. The angle of repose (AOR) testing is a standard test method used to calibrate the overall behavior of simulated aggregates. In this study, AOR testing of coarse aggregate particles with SMA-11 gradation is modeled to investigate the effect of different parameters on the simulation results and to calibrate parameters. For this purpose, sensitivity analyses are performed for different factors, i.e., model object, AOR testing method, rolling friction coefficient, Young’s modulus, and surface energy. The results show that the selected Young’s modulus can be reduced by up to four orders of magnitude compared to the real Young’s modulus without affecting the simulation results. The model object, rolling friction coefficient, and surface energy are significant factors for determining the AOR, and the AOR testing method does not affect the parameter sensitivity. The conclusion indicates that investigation of sensitivity parameters facilitates the implementation of DEM applications for aggregate particles in road engineering.