This paper proposes an efficient simplified elastic–plastic analysis procedure using engineering formulas to perform strain-based fatigue design considering the plasticity that occurs in nuclear safety class 1 piping systems during severe seismic loads, and then presents the application results of the procedure to a pressurizer surge line system. The total strain amplitudes, fatigue assessment results, and total calculation time were compared between the proposed procedure and the detailed dynamic finite element elastic-plastic analysis. The comparison confirmed that the proposed analysis procedure can efficiently derive reasonable and conservative results for nuclear safety class 1 piping systems under severe seismic loads.

本文提出了一种有效的简化弹塑性分析程序，使用工程公式来执行基于应变的疲劳设计，考虑到在严重地震载荷下核安全 1 级管道系统中发生的塑性，然后将该程序的应用结果展示给增压器浪涌线系统。比较了所提出的程序和详细的动态有限元弹塑性分析之间的总应变幅度、疲劳评估结果和总计算时间。比较证实，所提出的分析程序可以有效地为严重地震载荷下的核安全 1 级管道系统得出合理和保守的结果。