Analysis of particle fracture by repeated stressing as damage accumulation

Breakage of particulate materials by repeated low-energy stressing events is an important subject in areas such as particle transport - both mechanical and pneumatic - and comminution. Recently, a mathematical model, based on continuum damage mechanics, has been proposed to describe fracture of particles subjected to repeated loading and has been applied to model breakage of single particles by repeated impacts in a drop weight apparatus. The present paper analyzes the model in greater detail by investigating how its only parameter varies with particle size and shape, demonstrating also its validity to describe repeated impacts of particles against an anvil, such as in drop and air-gun tests. In addition, a model is proposed to describe the size distribution of the progeny under low-energy stressing events.