基于随机多尺度力学模型的混凝土力学特性研究

MECHANICAL PROPERTY RESEARCH ON CONCRETE BASED ON RANDOM MULTI-SCALE MECHANICAL MODEL

提出一种混凝土材料宏观力学特性分析的新方法——随机多尺度力学模型分析方法。从描述混凝土材料的细观尺度入手,首先采用Monte Carlo法生成由骨料颗粒及砂浆基质组成的混凝土试件的随机骨料模型;然后采用材料特征单元尺度法来剖分有限元网格并投影到建立的随机骨料模型上,各单元网格的力学特性则采用复合材料等效化方法来确定。通过分析,给出了混凝土单轴拉伸情况下的变形及宏观应力-应变关系,结果与实验结果相比较为吻合;与细观力学模型相比,该文方法极大地节省了计算资源,具有高效性。

A new method with a random multi-scale mechanical model was proposed in the paper to analyze the macro mechanical properties of concrete materials.The method was described to start with the micro-scale of concrete,and the Monte Carlo method was used to generate the random aggregate model of concrete composed of aggregate particles and the mortar matrices.And then,the finite element grid was meshed based on a characteristic unit dimension,and the mesh grid was projected on the established random aggregate model.The mechanical properties of each element were determined by an equivalence method of composite-materials.The macroscopic stress-strain relationship and the deformation of concrete specimen under uniaxial tension based on the Random multi-scale mechanical model were given through the analysis,and the analysis results showed a good agreement with the experiment results.The method proposed in the paper greatly saves computing resources with high efficiency,compared with a micromechanical model.