中文摘要：

汽轮机在频繁启停时，蒸汽参数剧烈变化，引起汽轮机部件内部温度分布剧烈变化，从而产生较大的转子热变形和热振动．在考虑了材料随温度变化的基础上，采用有限元法，利用热-结构动力学耦合理论，研究了径向温差、不平衡、热弯曲以及不平衡和热弯曲联合作用对转子-轴承系统热振动特性的影响，找出了影响热振动特性的敏感参数．计算结果表明，热弯曲的产生改变了转子系统的振动特性，在转子系统的设计中应当充分考虑热弯曲的影响．

英文摘要：

The steam parameters change fiercely when steam turbine frequent start and stop alternatively. This causes the temperature distributions inside the steam turbine＇s parts with great gradient. Therefore the rotor comes into being great thermal distortion and vibration. Based on the consideration of the material＇s performance changed with temperature, the affecting factors, such as radial temperature difference, imbalance, thermal bending as well as the combination of imbalance with thermal bending, on the thermal vibration characteristics of the rotor-bearing system, were studied by means of the coupling theory of thermal-structure dynamics with finite element method. The sensitive parameters effecting on thermal vibration were found out. The calculations show that, the formation of rotor＇s thermal bending causes the vibration characteristics of the rotor system to be changed. So the effects of thermal bending on the rotor system should be fully considered during rotor＇s design.