<p>Simulation of deformational behavior of geomaterials by particle-based techniques is a challenging task due to the simplifying assumptions in the numerical models. The bonded particle model (BPM) is a particle-based DEM tool normally used to simulate the mechanical behavior of granular materials. In this work, 3D numerical direct shear tests were conducted to understand the relationship between friction and dilation angles of bonded particle systems. Dimensional analysis was used to scrutinize the impact of dimensionless micromechanical parameters on the mechanical response of the numerical model. Both spherical and irregular clustered particles were utilized in the simulations. The results of the numerical models were compared with the physical test data reported in the literature. It was shown that porosity, stiffness ratio (ratio of shear stiffness to normal stiffness of contact points), and particle shapes have the greatest impact on the friction and dilation angles. The results suggest that the BPM systems with spherical particles underestimate the friction angle, while the dilation angle is overestimated. In contrast, the BPM systems with clustered particles, show more realistic friction and dilation angles. Furthermore, consistent with the physical observations, the critical state friction angle appears greater when irregular particles are used in the numerical simulations.</p> Graphical Abstract <p></p>