对10kg转子进行自由状态和有气膜约束两种状态下的试验模态分析,试验结果给出了转子平动、锥动和一阶弯曲时的固有频率及其振型等模态参数,分析了轴承供气压力变化对轴系固有频率的影响.进行了轴系升降速试验,结果表明:气膜约束下的模态分析结果比自由状态下的更接近于升降速试验的结果.试验结果为气体轴系固有频率的确定以及控制参数的选取提供了依据,也为下一步轴系振动控制奠定了基础. The experimental modal analysis of the 10kg rotor under both free-state and gas-membrane constraints was carried out. The experimental results showed the modal parameters such as natural frequency and mode shape of the rotor during translational motion, cone motion and first-order bending. The influence of bearing gas supply pressure on the natural frequency of the shaft system was investigated.The test results of the shaft speed-up and down-going test results show that the results of modal analysis under the gas-film constraint are closer to the ascending and descending speed test than the free- It provides a basis for the determination of the natural frequency of the gas shaft system and the selection of control parameters, and also lays the foundation for the vibration control of the shaft system in the next step.