大型汽轮机部件低周疲劳安全寿命的设计和评定

文中提出了汽轮机部件低周疲劳安全寿命的设计和评定方法。介绍了汽轮机部件低周疲劳安全寿命的含义和计算方法。该方法以概率论和统计学为基础，把汽轮机部件的低周疲劳寿命处理为随机变量，对低周疲劳试验数据进行统计分析来确定材料低周疲劳寿命的分布参数，使用可靠性理论来确定汽轮机部件的低周疲劳安全寿命。文中给出了低周疲劳寿命服从正态分布和对数正态分布时汽轮机部件低周疲劳安全寿命的计算方法和应用实例。该方法考虑了汽轮机运行参数随机性和材料低周疲劳特性离散性的影响，为汽轮机部件低周疲劳寿命的设计、评定和诊断提供了科学的依据。

Low Cycle Fatigue Safe Life Design and Assesment of Large Steam Turbine Components

A method for the low cycle fatigue safe life expectation design and assessment of steam turbine components is presented. The purport and a calculation method of low cycle fatigue safe life design and assessment are expounded. The method is based on theories of probability and statistics, considering the low cycle fatigue life of steam turbine components to be a random variables, depending on concrete conditions. The low cycle fatigue life distribution parameters of the materials are estimated by statistical methods and low cycle fatigue test data. Low cycle fatigue safe life expectation of steam turbine components is calculated by applying the reliability theory. For low cycle fatigue life of steam turbine components with normal or a logarithmic normal distribution, a calculation method of the safe life expectation is given together with a practical example. The suggested method considers the effect of both randomness of steam turbine operational parameters and dispersity of the materials' low cycle fatigue properties which may be used to provide a scientific basis for low cycle fatigue life design and life assessment and life diagnosis of steam turbine components.