基于无损受力状态的混凝土弹塑性损伤本构模型

AN ELASTOPLASTIC DAMAGE CONSTITUTIVE MODEL FOR CONCRETE BASED ON UNDAMAGED STATE

在实验基础上得到了混凝土在理想无损伤状态下的应力-应变曲线。基于此理想无损伤曲线和损伤力学理论建立了一种新型的塑性与损伤相解耦的混凝土弹塑性损伤本构模型,其中塑性部分建立在有效应力空间,采用基于拉、压双重强化模式的屈服函数,塑性强化准则采用理想无损伤条件下的Ramberg-Osgood强化规律;损伤部分基于有效应力张量的正负分解,采用受拉和受压两个损伤变量反映两种不同的损伤状态,由塑性应变驱动的分段曲线损伤演化方程建立在理想无损伤应力-应变关系之上。数值模拟与实验结果的对比证明了该文模型的有效性。

The ideally undamaged stress-strain curve for concrete is obtained through experiments. Based on the undamaged curve and the damage mechanics theories, a new elastoplastic damage constitutive model for concrete is presented in which plasticity and damage are decoupled. The plasticity range is constructed in the effective stress space using the yield function with two hardening variables, and the hardening rule is given in the form of Ramberg-Osgood formulation on the basis of ideally undamaged state. The damage model is based on the decomposition of effective stress tensor. And two damage variables, one for tensile damage and the other for compressive damage are used to account for different damage states. The sectionalized damage evolution equations based on the undamaged state are driven by plastic strain. Finally the comparison between numerical simulations and experimental results illustrates the validity of the presented model.