| Rotating machinery including steam turbines, gas turbines, generators, motors, centrifugal compressor, turbine, aircraft engine and other mechanical equipment, are widely used in electric power, aviation, aerospace, chemical, textile, metallurgy and other economic areas. Along with the progress of the technology and the level of the modern industrialization, the rotating machine are going through a rapid development towards automatic and magnification, which place more requirements for the stability and reliability in the working of the rotating machines. The failure of rotary machine is caused by the fault of rotor system, mainly related with vibration. So how to design the rotor system to make it won’t invalidated owing to excessive vibration. This is It’s a major focus in present studying.The development of rotor dynamics has been summarized in the paper. Combined with the reliability theory, the rotor system sensitivity of reliability and the robust of rotor system are also designed. Object studied is a multi-span of the centrifugal compressor. Firstly, complex rotor system is simplified reasonably; dynamics model of rotor system is established. Dynamic characteristic of the rotor system is analyzed with the finite element method, the unbalance response and distribution of maximum vibratory displacement of the bearing is extracted in the post-processing stage. Secondly, the paper adopts neural network technology combined with FEM to fitting function relationship among the random variable with the displacement of response, with its high nonlinear mapping function and can approach arbitrary function. Finally, the reliability robust of rotor system is designed, according to the reliability-based sensitivity technique.Through the study of this thesis, a reliability robust design method have been summarized and explored to apply to the large-scale centrifugal compressor, to make sure vibration displacement of the rotor within the scope of the security operation. This product is designed to provide a theoretical reference period, while the production of reality is also of great significance. |
