热力学相容的混凝土各向异性单边损伤模型

微裂缝演化(损伤)引起的各向异性和单边效应，对于混凝土材料和结构的变形和内力有非常重要的影响. 在描述单边效应时，已有的各向异性损伤模型均会得出与热力学基本原理相矛盾的结论即损伤卸载时能量耗散不为零. 基于不可逆热力学和内变量理论，直接以材料柔度张量的增量作为损伤内变量，建立了各向异性单边损伤模型的一般形式，给出了热力学相容的投影算子，推导了模型的率本构关系.文中详细发展了模型的Newton-Raphson数值实现算法及其算法一致性模量，建立了合理的损伤准则和演化法则并应用于混凝土材料. 数值模拟结果初步验证了建议模型的有效性. 需要说明的是，模型完全构筑于热力学基础上，无需引入应变 等效或应变能等效等经验性假定. 

ON THERMODYNAMICALLY CONSISTENT ANISOTROPIC UNILATERAL DAMAGE MODEL FOR CONCRETE

The appropriate modeling of damage induced anisotropy and unilateral effects due to macrocracks evolution are rather crucial to predict the nonlinear responses of concrete material and structures.With the introduction of scalar,vector,second-order and fourth-order tensors,or even higher damage internal variables, continuum damage mechanics(CDM) is capable of macroscopically describing the influences of microcracks evolution on the nonlinear behavior of concrete and therefore has been widely adopted in the l...