【摘要】 基于损伤力学原理,通过引入损伤变量的方法,详细推导了ABAQUS中的损伤塑性本构模型,描述混凝土后继屈服阶段及其卸荷后的损伤机制和力学行为。此本构模型可考虑循环荷载条件下材料刚度退化和应变率的影响,适用于类似混凝土材料的脆性材料,如岩石等。以某水电站地下厂房洞室结构为例,进行二维动力时程非线性分析,考虑不同的刚度恢复权重因子和应变率相关性对结构损伤的影响。多个数值算例表明:洞室混凝土结构和其周围一定深度的围岩的损伤是一个渐进积累的过程;材料的率相关性效应并不是在地震动作用开始时就立即产生,而是在一段时间后,结构经历一定程度的损伤后才慢慢体现出来;此损伤塑性模型适合地震荷载等循环荷载作用下地下洞室结构的动力时程非线性分析,尤其是强震下采用此损伤塑性模型是合理和必要的。更多还原

【Abstract】 The authors give a comprehensive derivation of the concrete damaged plasticity model in ABAQUS,which is based on the damage mechanics and can describe the damaged mechanism of concrete during unloading in postfailure stage through introducing a damaged variable.The constitutive model can consider the stiffness degradation and strain rate under cyclic loading condition which is suitable for the analysis of concrete and other quasi-brittle materials,such as rock,mortar etc.In order to verify the feasibility of applying it to underground structures,a time-history dynamic nonlinearity analysis is achieved for a hydropower station underground structure which mainly considers the influence of different compression stiffness recovery factors and strain rate dependence to the damage of concrete and surrounding rocks.The simulation results indicate that the damage of underground structure is a progressive procedure;the rate dependent effect doesn’t immediately occur at the beginning of earthquake but gradually behaves after the understructures have undergone some damage.The results also prove that the damaged plasticity model is dramatically competent for the dynamic nonlinearity study of underground structure during seismic loading especially under strongly seismic loading.The conclusion could be used as a primary guidance to the anti-earthquake design for practical engineering.更多还原