混凝土徐变损伤演变方程及其在非线性徐变理论中的应用

An Evolution Equation for Creep Damage and Its Application to Nonlinear Creep of Concrete

本文运用连续介质损伤力学的基本方法分析混凝土在高应力下的非线性徐变,根据混凝土徐变过程中内部微裂缝的细观分析,建立了徐变损伤演变方程,同时得到弹性徐变耦合损伤后的非线性徐变本构方程,用所得到的方程分析了在低于长期强度的应力作用下的长期徐变和应力水平高于长期强度时的徐变破坏,计算的结果和一维非线性徐变实验数据符合得较好。

With the help of continuous damage mechanics,the nonlinear creep and creep failure of concrete under high sustained compressive stresses are studied in the paper.On the basis of submacro-analysis on the creep process in concrete,an evolution equation of creep damage is developed.At the same time,the constitutive equations of elastic creep coupled with damage are obtained.Using the equations,the authors have calculated the long-term nonlinear creep and creep failure when stresses are over the long-term sus -tained strength.The calculated results are in agreement with the nonlinear creep test data.