混凝土粘塑性动力损伤本构关系
A viscoplastic damage constitutive model for concrete
-
摘要: 从静力弹塑性损伤本构关系的基本框架出发, 综合考虑塑性应变与损伤演化的率敏感性, 建立了能够较为全面地描述混凝土在动力加载条件下非线性性能的混凝土黏塑性动力损伤本构模型. 为了考虑塑性应变的率敏感性, 基于Perzyna理论推导了有效应力空间黏塑性力学基本公式, 采用改进的Perzyna型动力演化方程, 将损伤静力演化方程推广到动力加载情形. 基于并联弹簧模型, 从概率论的角度推导给出了一维损伤静力演化方程,并基于能量等效应变的基本概念将其推广到多维损伤演化. 利用数值模拟, 计算得到了混凝土在不同应变率下的应力应变全曲线, 同时得到了一维动力提高因子和二维动力强度包络图, 数值结果与试验结果的对比表明了该模型的有效性.Abstract: Based on the static plastic damage framework forcontinuum, the dynamic-viscoplastic damage model for the nonlinear analysisof concrete structures under dynamic loading was developed in the presentpaper considering the rate-sensitivities of plastic strain and damageevolution. The Perzyna type viscoplasticity in the effective stress spacewas derived to account for the rate-sensitivity of the plastic strainevolution. The rate-dependent damage evolution was extended from the staticdamage evolution using the modified Perzyna type formulations. The uniaxialstatic damage evolution function was developed based on the parallel elementmodel. Then the multiaxial static damage evolution was established bysubstituting the energy equivalent strain into the uniaxial static damageevolution function. The stress-strain curves, the dynamic increase factorand the biaxial dynamic envelopes were simulated in the present paper. Theagreement between numerical results and experimental data indicates thevalidity of the proposed model.