反应堆压力容器主螺栓螺纹疲劳分析方法

摘要

Screw threads on studs connecting head and vessel flange of reactor pressure vessel is one of the representative regions with small margin of fatigue analysis among nuclear island primary equipment.Con-sidering structure of the stud and the hole on the head vessel,comparisons are made to optimize fatigue a-nalysis method of the screw threads in the aspect of simplifying method of the thread model,way of getting of the stresses,grouping and combining of transient loads of temperature and pressure,choosing and using of fatigue strength reduction factor Kf,ect.Conclusions about influences of all the above factors are summed up,and an effective method to maximize margins of fatigue analysis for screw threads are given. This method can be used for the design of reactor pressure vessel stud.%反应堆压力容器主螺栓螺纹是核岛设备疲劳分析中裕量偏小的典型部位之一.为优化螺纹疲劳数值分析方法,考虑主螺栓及主螺孔结构特点,从螺纹模型简化方式、应力提取及组合方式、瞬态温度和压力载荷叠加方式、疲劳强度减弱系数Kf取值及使用方法等方面,对反应堆压力容器主螺栓螺纹疲劳性能进行对比分析,总结出各因素对疲劳累积使用系数的影响规律,推荐一套较为合理、有效的计算方法,以提升螺纹疲劳分析裕量,从而为螺栓结构设计提供参考.