考虑细观缺陷和静力本构的混凝土动力本构模型

Dynamic constitutive equations forconcrete based on meso-cracks anda static constitutive model

混凝土的动力特性一直是研究人员关心的一个问题。经典的细观力学方法虽然可以较好地描述混凝土的性质,但计算比较复杂。该文提出了一种考虑细观缺陷的混凝土动力本构模型,该模型不需要进行繁琐的计算,直接在混凝土静力应力应变关系基础上,考虑混凝土断裂韧度和微裂纹应力强度因子在静动力荷载下的差异,推求动力荷载下的应力应变关系。与试验结果对比表明,本文提出的理论模型能较好地反映混凝土的动力特性。

The dynamic properties of concrete have attracted much attention due to its engineering importance. Classic micromechanics can accurately describe concrete properties, but the analyses require complex computations. Simple dynamic constitutive equations with no empirical constants were developed for concrete based on meso-cracks and a static constitutive model. The concrete stress-strain relationship considers the differences between the concrete fracture toughness and the stress intensity factor of meso-cracks for static and dynamic loadings. Comparison of the theoretical results with experimental data shows that the model can accurately describe the dynamic properties of concrete.