中文摘要：

引入拉伸损伤变量和剪切损伤变量来共同描述损伤对混凝土宏观力学性能的劣化,采用带拉断的Mohr-Coulomb准则作为塑性损伤模型的屈服准则以及非关联的Drucker-Parager塑性势函数,在热力学和连续损伤理论的框架内建立损伤准则和损伤演化方程,提出了一种改进的混凝土塑性损伤模型,并采用基于完全隐式的向后Eu-ler积分算法进行应力更新。在ABAQUS平台上,采用UMAT进行改进的塑性损伤本构模型的二次开发,并进行了单轴和多轴数值验证。计算结果表明：数值结果和理论曲线及试验成果吻合很好,验证了本构模型的合理性。

英文摘要：

In view of the characteristics of stress and damage states of concrete structures,tensile and shear damage variables were introduced to describe the influence of micro-crack on the degradation of micromechanical properties.A novel plastic-damage constitutive model that employed a yield criterion based on Mohr-Coulomb criterion with Rankine was proposed.Additionally,the nonassociated flow rule was assumed and the Drucker-Parager function was adopted.The implicit backward Euler integration algorithm was applied to update stress.A subroutine on ABAQUS platform was developed for the validation of the damaged-plasticity model and well agreement was achieved between the analytical result and numerical result,which verified the rationality of the constitutive model.