采用变化附加阻尼的快堆堆芯组件抗震分析方法的研究

Methodology for Seismic Analysis of FBR Core Assembly Using Variable Added Damping

对快堆堆芯组件进行的抗震分析需要考虑冷却剂与堆芯组件之间的流固耦合作用。在之前的分析中,大多数人将流体附加阻尼处理为定值。实际上冷却剂对组件的作用还随着组件间的间隙变化而变化,其带来的附加阻尼应为变量。为更准确地模拟堆芯组件的振动,本文采用变化附加阻尼对快堆堆芯组件的抗震分析方法进行了研究。建立了快堆堆芯单排(5根)堆芯组件的抗震分析计算模型,对该模型进行了附加阻尼为定值和随间隙变化两种情况下的抗震分析,结果显示了考虑变化附加阻尼的堆芯组件抗震分析方法的可行性与有效性。本文所使用的模拟方法更为贴近堆芯组件的振动情况,为更为真实地模拟快堆堆芯组件的地震响应打下基础,这也有助于减少结构设计的保守性,具有一定的工程价值。

It is necessary to consider the fluid solid coupling effect due to the interaction between coolant and core assembly when analyzing the seismic performance of the FBR core assembly. The added damping was treated mostly as a constant in previous researches. In fact, the effect on assemblies from the coolant depends strongly on the gap between the core assemblies, and the damping should be considered as a variable. In order to simulate the vibration of the core assembly more accurately, the methodology for the seismic analysis of FBR core assemblies using variable added damping was studied. In this paper, the seismic analysis model of one single row of core assemblies （5 assemblies） of FBR was established. By comparing the two kinds of added damping models, the constant and variable ones respectively, the results show that the seismic analysis of the core assemblies with variable added damping is feasible and effective. Meanwhile, the simulation method used in this paper can obtain more precise approximation of the vibration of the core assembly and lays the foundation for more realistically simulating the seismic response of reactor core assemblies. It also helps to reduce the conservative margin of the structural design and is meaningful in engineering application.