混凝土弹塑性多轴损伤模型及其应用

针对混凝土多轴应力状态下各向异性损伤的特点,建立了各向异性弹塑性损伤模型.该模型具有可清晰地表征混凝土的渐进破坏过程和表达当前损伤水平及结构破坏趋势的优点.引入了一个应力状态因子,用以表征当前应力状态在应力空间中距离破坏面的程度,从而对损伤演化方程进行了改进以考虑多轴效应.此外,在三轴破坏准则的基础上,还建立了考虑混凝土各向异性损伤破坏的多轴损伤破坏准则,其中包含了塑性、损伤内变量和有效主应力的影响.本模型可有效地表达出混凝土的各向异性和多轴损伤特点.

A multiaxial anisotropic elastoplastic damage model for concrete and its application

In view of the anisotropic damage characteristics of concrete under multiaxial stress state,an anisotropic elastoplastic damage model is presented.It has the advantages of expressing the failure process progressively,displaying the damage level and failure trend clearly.A stress state factor reflecting the degree of the current stress state apart from the failure surface in stress space is introduced, so that the damage evolution equation can be improved to take account of multiaxial effect.In addition,based on the triaxial failure criterion,an isotropic multiaxial damage failure criterion is established,in which the attribute of internal plastic and damage variables and effective principle stresses are included.The proposed model reveals the anisotropic multiaxial damage characteristics of concrete effectively.