GB/T 4732-2024《压力容器分析设计》中疲劳免除准则一的证明与应用

Interpretation and Application of Screening Criteria One for Fatigue in GB/T 4732-2024 “Pressure Vessels Design by Analysis”

摘要: 疲劳是压力容器中重要的失效模式之一，特别是针对复杂的工况条件，实施起来费时又费力。实际上，针对一些循环次数较少或者载荷应力水平不高的压力容器来说，在一定条件下，疲劳分析是可以免除的。我国新版压力容器分析设计GB/T 4732.4-2024中提供了三种疲劳评定免除准则。其中，疲劳评定免除准则一相比于JB 4732-1995在内容和表述上做了较大的修订，一方面扩大了疲劳免除准则的适用范围，另一方面根据循环次数的不同调整了相应的压力波动范围限值。本文对其修订背后的原理进行了详细的解读和分析，阐述了各个情况下压力波动百分比限值的来源，并通过应用举例阐述了其实施步骤和计算方法，旨在为工程设计人员更好地理解和运用新标准提供参考。

Abstract: Fatigue is one of the important failure modes in pressure vessels, which is time-consuming and laborious to implement for complex loading conditions. In fact, the fatigue analysis can be screened for some pressure vessels with a low number of cycles or a low load stress level under certain conditions. Three fatigue assessment screening criteria are provided in the newly revised standard GB/T 4732-2024 “Pressure Vessels Design by Analysis”. The contents and expressions of screening criteria one are revised significantly in GB/T 4732-2024 comparing with JB 4732. On the one hand, the application range of fatigue assessment screening criteria is expended, on the other hand, the corresponding pressure fluctuation range limit value are adjusted according to the different number of cycles. In this paper, the principles behind the revision are interpreted and analyzed in detail, and the source of the pressure fluctuation percentage limits in each case are described. The implementation steps and calculation methods are described through the application example with a view to providing useful reference for engineering designers to better understand and apply the new standard.