Sphere discontinuous deformation analysis simulation of single-particle breakage of ballast based on voxelization and amplification by contact number

In this study, the sphere discontinuous deformation analysis (SDDA) method combined with the voxelization method and amplification by the contact number method are adopted for single-particle crushing modeling of ballast particles with realistic shapes. The effects of loading rate, particle reconstruction method, and particle placement on the crushing behaviour are discussed. The results verify that the proposed approach of a single-particle crushing model using amplification by contact number can more accurately simulate the crushing process of ballast particles in terms of displacement-load curve, and crack patterns. As the loading rate increases, the simulation changes from quasi-static loading to impact loading. In addition, the method of gradient descent is used to reach the minimum potential state of ballast, where particle rotation is skipped during the whole crushing process with less computing cost. This study provides an effective method for simulating single-particle breakage of ballast in the SDDA framework.