核电主设备分析法设计中应力线性化路径可靠性及优化分析

Reliability and Optimal Analysis for Design by Analysis of Stress Linearization Path in Nuclear Power Equipment

分析法设计是核电主设备设计的主要方法之一。该方法将结构设计或评定中各输入参量进行偏于安全的假设,以安全-不安全定性反映主设备设计的结构完整性状态。在确定性分析法设计的基础上,本研究基于概率统计理论,利用可靠性及优化分析方法,综合考虑结构设计或评定中涉及的主观不确定性因素(应力线性化路径选取),选取核电主设备典型结构形式——蒸汽发生器过渡锥体段为研究案例,首先对影响应力线性化路径选取的参数进行敏感性分析。随后,优化出最佳应力线性化路径。本研究方法为工程设计中应力线性化路径的选取提供建议。同时,该方法对可靠性理论在ASME核电规范与标准的分析法设计中的应用具有积极意义。

Design by analysis is one of the main methods for nuclear power equipment design.The structure integrity was judged using the safety-factor based on deterministic approach providing that safety margins of input parameters are sufficient in the design by analysis.In practical engineering,nondeterministic variables exist,such as geometry,material properties,occurrence of beyond design basic loads etc.Based on the design by analysis,the reliability and optimal analysis methods were introduced in thebasic design or assessment by considering uncertainty of the subjective input variables（such as stress linearization paths）.The transition cone of steam generator which is a typical structure of nuclear key component was chosen as a research case in this study.First,the sensitivity analysis was carried out to select the parameters which have the greatest influence on the stress linearization path,and then the best path was optimized by optimal analysis.The methods used in this study provide some suggestions for the selection of stress linearization path for engineering design.Meanwhile,these methods have a positive meaning to the application of reliability theory in the design by analysis of ASME codes and standards.