小支管振动疲劳应力及循环统计方法比较  

Comparison of the Vibration Fatigue Stress and Cyclic Statistical Methods of Small Branch Pipe

作　　者：汪昌勇 何超[1,2] 周强 樊卿 李涛 帅志昂 WANG Changyong;HE Chao;ZHOU Qiang;FAN Qing;LI Tao;SHUAI Zhiang(Nuclear Power Institute of China,Chengdu,Sichuan Prov.610200,China;Chengdu Hezong Nuclear Power Engineering Co.,Ltd.,Chengdu,Sichuan Prov.610200,China)

机构地区：[1]中国核动力研究设计院,四川成都610200 [2]成都核总核动力研究设计工程有限公司,四川成都610200

出　　处：《中国核电》2025年第1期100-106,共7页China Nuclear Power

摘　　要：针对核电厂现场小支管振动疲劳损伤评估不同方法的适用性问题,ASME规范提出了主应力方向不变及最大最小循环计数法两种方法对管道进行应力评估,其中,管道包括核电厂现场的主管以及小支管,以某核电厂现场小支管振动应变数据作为计算输入,基于适用于管道振动疲劳应力计算的Mises应力符号修正法、ASME规范提出的应力计算方法分别计算小支管振动应力,通过主流的雨流计数法和最大最小循环计数法统计不同应力计算方法计算的应力范围和循环次数,并对小支管统计结果及疲劳损伤因子作比较分析。研究表明,在应力计算方法上,采用主应力方向不变的计算方法计算的结果不保守,用于评估小支管振动疲劳存在一定风险,Mises应力符号修正法用于评估小支管针振动疲劳更为合理;在循环统计方法上,最大最小循环计数法统计得到的累计疲劳损伤结果最为保守,同等算力下,最大最小循环计数法计算效率远低于雨流计数法的计算效率。In response to the applicability of different methods for evaluating the vibration fatigue damage of small branch pipes in nuclear power plant,the ASME code proposes two methods for stress assessment of pipelines:the constant principal stress direction and the maximum-minimum cycle counting method.The pipeline includes the main pipe and small branch pipes on the site of nuclear power plant.The vibration strain data of small branch pipes on the site of a certain nuclear power plant is used as the calculation input.Based on the Mises stress symbol correction method applicable to pipeline vibration fatigue stress calculation and the stress calculation method proposed by the ASME code,the vibration stress of small branch pipes is calculated separately.The stress range and cycle times calculated by different stress calculation methods are statistically analyzed using mainstream rain flow counting method and the maximum-minimum cycle counting method,and the statistical results and fatigue damage factors of small branch pipes are compared and analyzed.Study has shown that using a stress calculation method where the principal stress direction remains unchanged is not conservative,and there is a certain risk in evaluating the vibration fatigue of small branch pipes.The Mises stress symbol correction method is more reasonable for evaluating the vibration fatigue of small branch pipe needles.In terms of cyclic statistical methods,the cumulative fatigue damage results obtained by the maximum-minimum cycle counting method are the most conservative.Under the same computing power,the calculation efficiency of the maximum-minimum cycle counting method is much lower than that of the rain flow counting method.

关 键 词：小支管 疲劳损伤 雨流计数法 最大最小循环计数法 应力范围 循环次数 

分 类 号：TM623[电气工程—电力系统及自动化]