complete modelling of a rotor-bearing-housing system

Due to the inaccessibility to rotating parts of the rotor the only way to flaw detection is measuring vibrations on the fixed portions such as surfaces of housing the bearings. It is common that in industry with measure vibrations of surfaces the housings at three direction and analyze it, predict and solve the created bug type. Take the effects of the housing can be help to accurately predict the rotor behavior at the measured response of the rotor using the analytical methods. Aims of this paper are modeling a full system of rotor-bearing-housing and considering the housing effects. For this, firstly subsystem of rotor-bearings is modeling using the Riley’s continuous beam theory and assumed modes method. Also a complete finite element model and a simple spring-mass model of the housing is made. Then, the forces exerted from the subsystem of rotor-bearing is calculated using the Newmark method and by applying on model of the housing, the responses time, curves of the deformation and frequency spectrums are drawn. The present study has been able to modeling properly the complete rotor-bearings-housing system. Furthermore the inadequate of the simple spring-mass model due to large errors and inability to accurately modeling the vibrating behavior of housing has acknowledged. Studies have shown that despite the lack of the axial force in the rotor-bearing subsystem, the housing will vibrate in axial direction. In addition with despite the equality of all conditions in the rotor-bearings, will not be expected an equal response in all direction of the housing. Also by considering the housing effects, domain the graphs of frequency spectrum will be reduced, particularly at high frequencies.