基 于 突 变 刚 度 和 阻 尼 的 变 转 速 动 力 涡 轮 转 子模 态 转 换 振 动 控 制 方 法

In order to solve the problem of excessive vibration caused by multiple bending modes during the operation of a certain type of variable speed power turbine rotor，based on the modal characteristics and support layout of the power turbine rotor，a vibration control method of mode transition based on abrupt stiffness and damping is proposed，the vibration reduction characteristics of this method was analyzed and verified through a combination of numerical calculation and experiment. The results show that this method can realize the mode transition of the rotor system by changing the stiffness and damping instantly and simultaneously，finally achieving the purpose of avoiding resonance peaks and suppressing vibration. Through the control of mode transition，the first two resonance peaks of the variable speed power turbine rotor are reduced by 55.12% and 49.08% respectively，the strain energy ratios of the first two stages of shaft system are reduced by 81.21% and 48.23% respectively，and the safe operating range is extended from 0～32.5% maximum working speed to 0～100% maximum working speed. When adopting mode transition for vibration control，the orbit of the variable speed power turbine rotor shows a phenomenon of retrace wave，and the spectrum diagram contains the subharmonic，reverse precession and continuous spectrum components，and the system runs in a relatively chaotic way.