Fatigue life prediction of motor-generator rotor for pumped-storage plant

• Published in: Engineering failure analysis 2017-09, Vol.79, p.8-24
• Main Authors: Nie, Liangliang, Zhang, Mengxiao, Zhu, Libei, Pang, Jianchao, Yao, Ge, Mao, Yunxian, Chen, Man, Zhang, Zhefeng
• Format: Article
• Language: English
• Subjects: Fatigue influencing factor; Fatigue life prediction; Key part life method; Motor-generator rotor; Steel sheet
• ISSN: 1350-6307; 1873-1961
• DOI: 10.1016/j.engfailanal.2017.03.013

To predict the fatigue life of motor-generator rotor in a pumped-storage plant, the most dangerous position of the rotor under the highest applied load was found to be at the dovetail of magnetic pole and yoke after failure analysis and stress condition analysis. In this work, two types of steel sheets used to manufacture those parts were chosen to study the microstructures and mechanical properties, especially the fatigue properties. Based on those results, some methods including widely applied Forschungskuratorium Maschinenbau (FKM) method and modified one were used to predict fatigue life of the key parts. Considering possible influencing factors, based on the fatigue theories or methods to modify mean stress and predict fatigue life, a novel method, named key part life (KPL) method, was proposed briefly. The KPL method not only suits well for the motor-generator rotor, but also provides a new idea for life prediction of parts in engineering field. •The fatigue property of steel sheets of magnetic pole and yoke are studied.•Some key influence factors of the fatigue life on component are analyzed and confirmed.•The Goodman mean stress correction, Miner and Corten-Dolan damage rules are found to suit for the components.•To predict the fatigue life of components, the key part life method is easy and simple.