汽轮机长叶片弹塑性分析及寿命评估方法

在当前汽轮机的某些极限设计工况下，基于无限寿命的线弹性考核规范已经无法满足当前的工程设计要求，需要发展弹塑性强度计算方法以及有工程意义的强度评估准则，并在此基础上引入低周疲劳寿命考核方法对零部件寿命进行分析预测.对某汽轮机末级长叶片进行弹塑性有限元分析，提出将基于局部应力 应变法的低周疲劳分析理论与商用疲劳分析软件相结合的方法对叶片进行强度设计的方法和流程.结果表明：所提出的弹塑性分析以及疲劳寿命评估方法能很好地反映长叶片的实际强度，有助于进一步制定一套完善的适合工程应用的长叶片强度评估标准，从而提高叶片的设计水平.

Elastoplastic analysis and fatigue life assessment method for steam turbine long blade

In some ultimate design conditions of current steam turbines, the linear elastic infinite life assessment specification is unable to meet the current engineering design requirements. The elastoplastic strength calculation method and the strength assessment criteria for engineering should be developed, based on which the low cycle fatigue life assessment method should be introduced into the analysis and prediction on the life of parts. The elastoplastic finite element analysis on the last stage long blade of a steam turbine is performed. Combing commercial fatigue analysis software with the low cycle fatigue analysis theory, based on local stress stress method, the blade strength design method and procedure are proposed. The results indicate that, the method of elastoplastic analysis and fatigue life assessment can well reflect the actual strength of blades, which is helpful to propose a perfect long blade strength assessment standard for engineering application and improve the long blade design level.