摘要
提出了一种基于NHR200-Ⅱ供热堆燃料组件定位格架的简化模型。简化建模方法包括2方面:将定位格架上的内刚凸及三弯弹簧用非线性连接器代替;使用梁单元代替实际燃料棒。结合前期关于NHR200-Ⅱ定位格架的研究成果,确定了非线性连接器的刚度,并通过有限元软件建立了燃料组件简化前后的1×2局部子模型,分析了其固有频率与碰撞特性,证明了简化建模方法的有效性。随后,该简化方法被应用于全尺寸的9×9定位格架模型,研究了格架夹持能力对动力学特性的影响,结果表明,该简化方法可以有效地模拟不同夹紧程度下格架的地震谱响应。综上,从有限元建模角度来看,本文提出的基于NHR200-Ⅱ燃料组件定位格架的方法是有效的。
A simplified modelling method for the spacer grid of NHR200-Ⅱ fuel assembly is proposed to increase the computational efficiency in the dynamic analysis. It includes the replacement of the grid inside the dimples and three-arc springs with the non-linear connectors, and the replacement of the fuel rods with beam elements. The stiffness of connectors was derived from previous experiments of NHR200-Ⅱ spacer grid. Natural frequency analysis and impact simulation were performed by a 1×2 sub-model of the fuel assembly to verify this method. Then, this simplified method was applied to a full-scale 9×9 spacer grid model, to study the effects of the grid clamping ability on its dynamic characteristics. The results suggest that this simplified approach can give a reasonable response when induced by a seismic load at different clamping levels. In conclusion, from the modelling point of view, the proposed simplified method for NHR200-Ⅱ spacer grid is effective.
作者
王淅铖
王鼎渠
蒋跃元
李松阳
Wang Xicheng;Wang Dingqu;Jiang Yueyuan;Li Songyang(Institute of Nuclear and New Energy Technology,Tsinghua University,Beijing,100084,China;Key Laboratory of Advanced Reactor Engineering and Safety,Ministry of Education of China,Tsinghua University,Beijing,100084,China)
出处
《核动力工程》
EI
CAS
CSCD
北大核心
2021年第4期105-111,共7页
Nuclear Power Engineering
关键词
低温供热堆
燃料组件
定位格架
简化建模
动力学分析
Nuclear heating reactor
Fuel assembly
Spacer grid
Simplified method
Dynamic analysis
