混凝土单轴压缩破坏过程的三维细观数值模拟

Three-Dimensional Numerical Simulation on Meso-Level of Uniaxial Failure Process in Concrete

从细观力学的角度出发,将混凝土视为由骨料、砂浆及二者之间的界面所组成的三相复合材料,利用蒙特卡罗方法,产生骨料在试件中的随机位置,建立了混凝土圆柱体试件三维数值模型。进行单元划分,对试件中骨料、砂浆和界面单元的材料号进行自动识别及赋值。通过三个计算方案研究了混凝土单轴压缩下的力学性能及破坏过程,模拟了混凝土材料从裂纹的萌生、扩展、贯通直到宏观裂纹产生导致破坏的过程。结果表明,该数值模型及计算方法能够较好地反映混凝土在单轴荷载作用下的力学特性。

Based on meso-mechanics, concrete is taken as three-phase composites consisting of aggregate, mortar and bond between aggregate and mortar. The random position of aggregate in specimen is generated by Monte-Carlo method. 3-D numerical model of the cylinder specimen of concrete is established. The material number of aggregate, mortar and bond element is identified automatically and evaluated. The mechanical performance and failure process of concrete subjected to uniaxial compressive stress are studied, the failure process caused by the initiation, propagation and coalescence of cracks is simulated. It is shown that that numerical mode and calculation means are used to simulate the mechanical behaviors of concrete in uniaxial load.