基于统计断裂理论的混凝土本构关系的研究

以圆盘裂纹模型模拟混凝土内部的缺陷，基于统计断裂理论推导出了多轴应力下混凝土的损伤统计模型，并根据应变等价假说，建立了包含损伤的混凝土的基本本构关系。研究结果表明：混凝土中裂纹面之间的摩擦系数不同，混凝土的应力一应变曲线就不同，摩擦系数越大，混凝土的强度就越高；围压越大，混凝土的强度就越大。随着应力、应变的增大，损伤也随之增大，应力一应变关系也由线性变化为非线性；当混凝土的其他材性参数相同时，Weibull模量m越大，混凝土的强度就越小。这些均与当前研究成果相吻合。

Research on Constitutive Relation for Concrete Materials Based on Statistical Fracture Theory

By means of selecting penny shaped crack model to simulate the defects in concrete,the damage model for concrete under multiaxial stress state was developed based on statistical fracture theory.Further than that,according to the equivalent hypothesis of strain,a constitutive relation containing damage model was established.At last,according to this study,the following conclusions could be drawn as: the greater the friction factor of the crack's plan was,the greater the strength of concrete was.Because of the friction between the crack's plan,the greater the confining pressure was,the greater the strength was;the bigger the Weibull's model m of concrete was,the less the strength was. These conclusions were in a good accordance with the study results by now.