Experimental study and theoretical analysis on ballast particle crushing based on energy dissipation and release

Existing particle crushing models and crushing criteria relying on the stress–strain state have the limitations of inaccuracy and single crushing behavior. It is well known that energy is the essential factor that drives particle crushing. This paper aims to reveal the crushing process of ballast particles more accurately from the perspective of energy. In this study, a series of single-particle uniaxial compression tests (SPUCT) were conducted using a high-speed camera system. The multi-stage crushing behavior and crushing characteristics of the particles have then been investigated. Energy state during particle crushing was analyzed. Finally, an energy-based multi-stage crushing model and crushing criterion for particles were proposed and validated by performing SPUCT on 10 new particles. The results show that: there is a significant difference between the characteristic stress-characteristic strain states when particles with similar shapes and sizes are crushed, the proposed multi-stage crushing theory accurately explains this complex crushing behavior; The evolution of the input energy, strain energy, and dissipation energy of the particles is consistent with the crushing characteristics; The energy-based multi-stage crushing model can avoid the limitation of using the characteristic stress-characteristic strain states, and the energy-based multi-stage crushing criterion can effectively capture the crushing behavior of particles. This study is very helpful in elucidating the mechanism of particle crushing from the perspective of energy evolution.