Currently many researchers studied size effect on the crushing strengths of rock particles

but they rarely considered the complex shapes and internal structures of heterogeneity. By the stochastic granular discontinuous deformation method (SGDD)

numerical was employed to simulate the single particle compression tests for rock particles with five different sizes. Particle crushing is simulated by introducing zero-thickness interface element and cohesive zone in SGDD model. Then we studied the influence of interface strength on particle crushing

and analysed size effect on the crushing strengths of rock particles using Weibull model. Comparing with single grain compression test indoor

the SGDD method makes the crushing process of single particle compression very realistic. Every compressive curve shows the same trend

that is

the curves increase sharply before reaching the peak force and followed by a sharp drop at fatal breakage. The peak stress is the strength of particle crushing. Crushing strengths in every group of particles satisfy the Weibull distribution well with an average Weibull modulus of 2.48. In addition

the crushing strengths among different groups of particles shows that the characteristic strengths decrease with the increase of particle size. The characteristic strengths and particle sizes obey a power law with an exponent of -0.163

less than the prediction of Weibull model.