关键词: 转子系统, 热振动, 热应力, 有限单元法, 耦合响应

Abstract: Thermal buckling is a common fault found in rotor system. The effect of steady-temperature field on the vibrational characteristics of rotor system of a certain turbine unit was studied by means of FEM and the coupling theory of thermal-structure dynamics. Comparing the unbalance response, thermal buckling response and the response coupling both together, the effects of steady temperature field, operational rotational speed on thermal vibration characteristics were discussed in detail with the sensitive parameters affecting thermal vibration found out. The results showed that the stiffness matrix of the rotor system is redistributed because of thermal buckling, thus resulting in the significant decrease in the first critical speed of the rotor system due to the thermal vibration. At the same time, the thermal buckling changes the balance position and causes the rotor system to vibrate periodically around a new balance position. The calculated results offer a theoretical foundation on which the design and fault diagnosis of rotor-bearing system are both available to avoid great thermal vibration.