基于能量耗散的多轴应力状态下混凝土损伤模型

Damage Model of Concrete under Multiaxial Stress State Based on Energy Dissipation

针对多轴应力状态下的混凝土损伤问题,假设损伤在主应力空间是正交各向异性的,选用Ottosen四参数破坏准则来确定多轴应力状态下混凝土破坏的极限应力,确定强度提高系数,结合Saenz提出的典型单轴本构模型建立等效单轴本构模型.根据Najar损伤理论,定义了综合损伤变量D,从能量耗散的角度提出一种用于多轴应力状态下的混凝土损伤模型.在计算损伤时采用精度较高的高斯积分法,通过对3种不同的三轴比例加载下损伤的研究,初步验证了模型的有效性,且模型形式简单,精度高,便于应用.

We investigate the damage behaviour of concrete under multiaxial stress state based on hypothesis that the damage is orthogonally aeolotropic in principal stress space.According to the Four-parameter failure criterion for concrete proposed by Ottosen,the ultimate stress of concrete under multiaxial stress state is determined,and then the enhanced coefficient of concrete strength due to multiaxial stress state is also fixed.Combined with the typical constitutive relation presented by Saenz,an equivalent unia...