混凝土楔入劈拉和三点弯曲断裂过程的细观数值模拟

Mesoscale simulation on fracture process of wedge splitting and three-point bending of concrete

基于离散元思想和Voronoi单元划分技术,利用混凝土细观刚体弹簧元模型,开展了混凝土楔入劈拉试件和三点弯曲切口梁的断裂过程数值仿真分析。从裂缝开展过程、试件破坏形态、荷载-张口位移曲线(P-CMOD)和断裂能等方面,将数值分析结果与已有的试验结果进行了对比。结果表明,细观刚体弹簧元法较准确地模拟了混凝土楔入劈拉试件和三点弯曲切口梁断裂过程。最后,分析了缝高比和骨料体积含量对混凝土断裂过程的影响规律,发现断裂能随骨料体积含量呈单调递增趋势。

Based on the discrete element method and Voronoi diagram technology, in this paper, the mesoscale Rigid Body Spring Model （RBSM） for simulating the fracture process of concrete was used to conduct the numerical analysis of the fracture process of concrete wedge splitting specimens and three-point bending notched concrete beams. The obtained results were then compared with available experimental results in terms of the process of crack propagation,the failure patterns of specimens , load- CMOD behaviour and fracture energy. It is shown that the mesoscale RBSM can be accurately applied to simulate the fracture process of concrete wedge splitting specimens and three-point bending notched concrete beams. The effects of different ratio of aiD and aggregate volume contents on the fracture process of concrete were also investigated and it is found that the fracture energy of specimens becomes higher with the increasing of the aggregate volume contents.