考虑微裂纹演化时间效应的混凝土动力损伤本构模型

A Dynamic Constitutive Damage Model Considering Rate-Dependence of Micro-cracks Evolution for Concrete

摘要:

在混凝土静力弹塑性损伤理论的基础上，提出有效损伤驱动力的概念，引入微惯性和微黏性以考虑混凝土微细观裂纹动力演化的率敏感性所导致的材料应变率效应，建立了适用于强动力作用下混凝土结构响应分析的动力损伤本构模型。利用数值分析得到的混凝土应力应变全曲线和动力提高因子表明该模型能够反映材料在中、高应变率作用下的动力力学性能。对Hopkinson杆的数值模拟，也表明了所提出模型的有效性。

Abstract:

In this paper， a rate-dependent damage model was proposed by incorporating micro-inertia and micro-viscosity into the static elasto-plastic damage framework to account for the strain rate effect of concrete induced by the rate-dependence of micro-cracks. The stress-strain curves and dynamic increase factors of concrete strength obtained by numerical analysis indicate that the dynamic mechanical properties of the material at moderate and high strain rates can be well captured by the model. Furthermore， numerical simulations of a Hopkinson-bar test were performed and the analytical results were in good agreement with the experimental results， demonstrating the validity of the proposed model for the dynamic responses analysis of concrete structures exposed to high-rate loadings.