矿渣混合料侧限压缩的宏细观力学特征

Macro Mesoscopic Mechanical Properties of Slag Mixture in Confined Compression Tests

基于颗粒流PFC2D程序,分别建立了圆形颗粒和簇单元颗粒模拟的2种级配的矿渣混合料数值模型,研究了侧限压缩过程中应力-应变关系、体系力链及颗粒破碎和运动特征。结果表明:利用簇单元模拟得到的应力-应变曲线更加接近于实际,体系在加载过程中力链先增大,之后随着颗粒破碎而迅速变化,很快分散到整个体系中,骨架结构相应进行调整。这些也与颗粒的棱角分离、位置错动和孔隙填充很好的对应起来,从而较好的再现矿渣混合料的压密-破碎-再次压密的过程。

Based on particle flow code （PFC2D）, we set up two models of slag mixture with different granular composition using balls and clusters to model slag granules respectively, and studied stress-strain, force chain, granule motion and breakage in confined compression tests. The results show that the stress-strain relations are more close to actual by using clusters to model slag granules. In the loading process, force chains first increase, afterwards rapid change with granule breakage, and soon spread to the whole system. Meanwhile, the skeleton construction adjusts accordingly. These also correspond well to granular angular separation, location moving and pore filling. Consequently, the process of slag mixture＇s compaction- breakage- recompaction are good represented.