Prediction of bolt missing fault for multistage rotor by experimental test and analysis

Abstract

The high-pressure rotor of aero-engine is assembled by numerous bolts under high manufacture precision. The connected structure is subjected to both axial force and transverse vibration during service, which may result in individual bolt loosen. In this study, the influence of bolt missing on the dynamic characteristics is analyzed by numerical simulation. A test rig capable of impact and frequency sweeping experiment under axial tension was constructed. The vibration response features in the simulation were then extracted. The loss function of the mean absolute error and the decision method of extreme gradient boosting were used to predict the bolt missing position. The results show that the proposed model can reach a prediction precision of more than 90%. Moreover, the coefficient of determination evaluation index of the prediction effect reaches 0.9, which is significantly higher than those of other conventional models such as multivariate linear regression and multivariate adaptive regression spliness.

Research on the Influence of Disc–Drum Connection Bolt Preloading Rotor Assembly Modal Characteristics and Diagnosis Technology

“…Yue [20] analyzed the influence of missing bolts on the dynamic characteristics of high-pressure rotors using numerical simulation, and a rotor test bench was built that can carry out impact and frequency scanning experiments under axial tensile force. Based on the obtained vibration response characteristics, the loss function of the average absolute error and the extreme gradient boosting decision method are used to predict the missing position of the bolt.…”