本文通过在损伤张量中引入应变率的影响,提出了应变率相关的混凝土弹塑性损伤模型,用来模拟混凝土材料在动力工况下的力学行为.利用此模型对一重力坝进行了地震动超载响应分析,分别从损伤断裂程度和层面抗滑稳定两个方面对坝体进行了安全评价.结果表明,由于地震荷载引起的应变率在坝面的分布不同,坝面各处的动态性能变化不一致,由此引起的混凝土强度和刚度的变化对坝体的动力响应和安全评价有重要影响.
A new rate-dependent damage constitutive model for simulating the mechanical behaviors of concrete working in seismic condition is established by introducing the effect of strain rate into the damage tensor. The model is applied to analyze the seismic overload response of a typical concrete gravity dam and the safety of the dam is assessed from two aspects including the damaged degree and sliding resistance stability. The result indicates that the distribution of strain rate caused by seismic loading varies at the dam surface and significantly affects the dynamic response as well as the safety evaluation of the dam.