关键词: 堆石颗粒, 颗粒破碎, 破碎强度, Weibull统计分析, 尺寸效应

Abstract: 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.

Key words: rock particle, particle crushing, crushing strength, Weibull statistical analysis, size effect