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为反映骨料、砂浆及其之间的界面过渡区的组合特点和材料性能,基于材料细观非均匀性和有限元方法的混凝土破坏过程细观数值模拟需进行复杂、细致的网格剖分,导致了繁重的前处理工作和可观的计算量。该文对混凝土材料细观单元材质组成的单一化假定进行改进,将内嵌界面过渡区材料的规则化单元视为一种广义复合材料单元,建立了复合型界面损伤模型。采用等效方法确定单元的复合弹性关系,通过有限元法计算单元的局部应力;用细观层次上弹性力学性能的弱化描述单元组成材料的损伤,混凝土材料的破坏过程通过单元各组分的损伤模拟。应用该复合型界面损伤模型研究了混凝土试件的单轴拉伸破坏过程,细观数值模拟结果符合混凝土试件的宏观破坏特征,表明该模型可作为分析混凝土材料破坏过程的一种有效途径。
In order to reflect the combination characteristics and material properties of aggregate, mortar and interfacial transition zone, mesoscopic numerical simulation of concrete failure process based on material mesoscopic heterogeneity and finite element method requires complex and meticulous meshing , Resulting in heavy pre-processing and considerable computational effort. In this paper, the simplification assumption of the material composition of the concrete cell is improved, and the regularized cell of the interfacial transition zone material is treated as a kind of generalized composite cell. The composite interface damage model is established. Equivalent method is used to determine the compound elastic relation of the element, and the local stress of the element is calculated by the finite element method. The damage of element composition material is described by the weakening of the elastic mechanics performance on the microscopic level. The damage process of the concrete material is characterized by the damage simulation. The composite interface damage model was used to study the uniaxial tensile failure process of concrete specimens. The results of meso-numerical simulation are consistent with the macroscopic failure characteristics of concrete specimens. It is shown that the model can be used as an effective way to analyze the failure process of concrete materials.