Frequency Reliability and Sensitivity Analysis on the Rotor System

Multispan rotor system(H858 compressor) is studied in this paper. Based on the rotor dynamic theory, complex rotor system is simplified reasonably, and finite element model is established using finite element software(MSC.Patran&Nastran). The natural frequencies are obtained in the condition of bending vibration, and the functions of frequencies and variables are matched on the basis of the artificial neural network (ANN) technique. With the criterion that the absolute value of the difference between the natural frequency and forcing frequency, the reliability mode and the systems safety probability are defined, then the frequency reliability sensitivity analysis method is presented. And the equations of the related sensitivity with respect to mean values and variances are mathematically expressed. The reliability and sensitivity of rotor system are analyzed, which demonstrate the effectiveness and accuracy of the proposed method.