The Nonlinearity And Reliability Analysis Of Rotor System With Some Faults

Rotating machinery is one of the most important equipment in industry departments, and it is widely used in steam turbine, aeroengine and so on. Rotor-bearing system is the key part of the rotating machinery, and plays a significant role in many important fields of industry. A lot of high requirements for stability, load, efficiency, reliability and automation to rotating machinery have been made alone with the development of high speed, high-power and flexible. It is very significant to study the dynamics characteristic, stability and reliability of rotor systems.In the paper, dual-disc and muti-discs rotor-bearing system are investigated. Using modern dynamics theory, rotor dynamics theory and fracture theory, the stability of dual-disc over-hung rotor system combining the whirling with swinging with gyroscopic effect and the nonlinearity of twenty-freedom two-span elastic rotor system with crack fault or not are studied. Then the residual life of muti-discs rotor system with crack is calculated. The main works are:(1) The dynamic model and mobile differential equation of dual-disc over-hung rotor system combining the whirling with swinging with gyroscopic effect are established, and the system stability is studied with gyroscopic action or not by solving the continuation-shooting algorithm for periodic solution of nonlinear non-autonomous system and Floquet theory. The effects on the stability of the system are discussed with different length of over-hung axis and clearance.(2) A twenty-freedom non-linear dynamic model of two-span elastic rotor system with rub-impact fault and oil film force is established. The complex motion and chaos characteristics of symmetric, dissymmetric and rigid rotor system are numerically studied and compared, and discussed with different parameters.(3) A two-span elastic rotor system with crack fault model is established with rub-impact fault and oil film force. The complex motion characteristics of the system are numerically studied and discussed with different parameters, and compared with the case without the crack fault.(4) Using finite element software and crack propagation theory, the crack propagation and reliability of muti-discs rotor system are investigated. The residual life is gained, and the effects on the residual life of muti-discs system are discussed with different length of initialization depth of crack, fracture toughness and temperature.