汽轮机动叶片的可靠性设计方法

提出了汽轮机叶片可靠性设计方法,介绍了叶片可靠性的含义和计算方法。该方法以概率论和统计学为基础,把汽轮机叶片的静应力、动应力、叶片疲劳强度、叶片安全倍率、叶片振动频率和激振力频率处理为随机变量,通过试验数据的统计分析和计算,确定有关随机变量的分布参数。使用概率设计法、应力与强度干涉模型确定汽轮机叶片疲劳强度和振动设计的可靠度。文中给出了叶片疲劳强度的动应力设计法和安全倍率设计法以及第一种调频叶片、第二种调频叶片和整圈连接叶片组的振动可靠性设计的计算公式和一些应用实例。使用这些方法,可以在设计阶段确定汽轮机叶片设计的可靠度,为汽轮机叶片的可靠性设计提供了科学的依据。

Reliability Design Method for Steam Turbine Blades

A reliability design method for steam turbine blades is presented. The purport and calculation method of blasde reliability are introduced. Based on probability and statistics theory, the static stresses, dynamic stresses, endurance strength, safety ratios, vibration frequencies and exciting force frequencies of blades are taken as random variables, the distribution parameters of the random variables are determined by the statistic test data. The fatigue strength and vibration design reliability of turbine blades are estimated with probabilistic design method and interference models for stress distribution and strength distribution. Some formulas for dynamic stress design method, safety ratio design method of fatigue strength as well as vibration reliability design method of first kind of tunde blades, second kind of tuned blades and packet of blades on disk are provided together with some practical examples. With the reliability design method for steam turbine blades, the design reliability of steam turbine blades can be determined during the design stage.