基于最小可靠性安全系数的吊篮法兰强度评定方法  

Strength Evaluation Method of Barrel Flange Based on Minimum Reliability Safety Factor

作　　者：王东辉[1] 曾庆娜 龚建硕 孙博[2] 杨西 任羿[2] Wang Donghui;Zeng Qingna;Gong Jianshuo

机构地区：[1]中国核动力研究设计院核反应堆系统设计技术重点实验室 [2]北京航空航天大学可靠性与系统工程学院

出　　处：《工程机械》2020年第8期86-93,I0015,共9页Construction Machinery and Equipment

摘　　要：针对裕度设计无法考虑参数随机特性及安全裕度大的问题,提出基于最小可靠性安全系数的压水堆吊篮法兰强度评定方法。与许用安全系数方法相比,该方法包含了更多参数信息且不依赖于由经验确定的许用应力强度,结果更加准确。对压水堆吊篮法兰进行应力分析,得到法兰的一次薄膜应力及弯曲应力最大值,并对法兰进行强度评定。在应力分析的基础上考虑法兰各参数不确定性,通过多次仿真及分布拟合得到应力的分布函数及各参数的灵敏度,并计算吊篮法兰的最小可靠性安全系数。探究最小可靠性安全系数随分布类型及参数的变化规律,结果表明:不同分布对计算结果影响较小,在应力分布未知的情况下,选择对数正态分布进行表征可以得到偏安全的结果;在应力和强度的变异系数达到0.3时,最小可靠性安全系数仍然大于1,吊篮法兰的结构设计存在一定优化空间。In view of the problem that the random characteristics of parameters and large safety margin cannot be considered in margin design,a strength evaluation method for core barrel flange of pressurized water reactor based on minimum reliability safety factor is proposed.Compared with the allowable safety factor method,this method contains more parameter information and does not depend on the allowable stress strength determined by experience,so the result is more accurate.The maximum values of primary membrane stress and bending stress of the flange are obtained by stress analysis of the core barrel flange of pressurized water reactor,and the strength of the flange is evaluated.On the basis of stress analysis,the uncertainty of various parameters of the flanges is considered,the stress distribution function and the sensitivity of each parameter are obtained through multiple simulation and distribution fitting,and the minimum reliability safety factor of the core barrel flange is calculated.The variation rule of minimum reliability safety factor with distribution type and parameters is found out.The results show that different distributions have little influence on the calculation results,and when the stress distribution is unknown,choosing lognormal distribution to characterize can get a relatively safe result;when the variation coefficient of stress and strength reaches0.3,the minimum reliability safety factor is still greater than 1,and there is some space for optimization in the structural design of the core barrel flange.

关 键 词：结构可靠性 吊篮法兰 有限元分析 可靠性安全系数 强度评定 

分 类 号：TM623[电气工程—电力系统及自动化]