混凝土弹塑性损伤本构模型的动力扩展

Dynamic Extending of Elastic Plastic Damage Model for Concrete

摘要:

在静力弹塑性损伤实用本构模型的基础上，通过将损伤能量释放率阀值粘滞化，建议能考虑应变加载速率影响的实用本构模型。并将阻尼应力引入到本构模型中，使得建议的模型能直接在材料层次考虑刚度阻尼耗能影响。在此基础上，引入受拉塑性应变，延缓受拉损伤的发展，提高模型的稳定性。文中推导了该模型的计算公式并给出了详细数值算法，将建立的本构模型在ABAQUS中二次开发，通过对KOYNA重力坝动力隐式分析表明：刚度阻尼的能量耗散作用能显著增强动力隐式分析的稳定性，引入受拉塑性应变后能增强模型数值稳定性，提高模型计算效率，同时应变率效应对结构的位移反应有一定的影响，且能进一步提高模型的数值稳定性。

Abstract:

Concrete exhibits strain-rate sensitivity during dynamic tests. In this paper, the practical elastic plastic damage model for concrete under static loading previously proposed by the authors is extended to account for the concrete strain-rate through the viscous regularization of damage variables. Stiffness damp stress is introduced into the model to consider the energy dissipation at the material scale. Tension plastic strain is introduced to the model to relax the descending and damage development. The proposed model is developed in ABAQUS, the nonlinear analysis of Koyna concrete dam indicates that the stiffness damp can observably enhance the stability of nonlinear dynamic implicit analysis. The introduction of tension plastic strain can also improve the calculation effect, and strain-rate sensitivity can affect the displacement reflect of the structure as well as improve the numerical stability.