Friction Heat Effect On Vibration Responses Of Nonlinear Rotor In Full Annular Rubbing

Rubbing between rotating and static is a harmful phenomenon with a complex process.The friction between rotor and stator makes the heat accumulate at the contact point,and the thermal deflection occurs at the rotor due to the uneven heat.Then the distribution of the unbalance magnitude at the rotor changes and the vibration responses changes.In recent years,more and more attention has been paid to the friction heat effect of the rub impact in the rotor system on the vibration characteristics.Aiming at the analysis of the friction heat effect on vibration responses of the rotor system,the finite element model of rotor-to-casing system is established first,and the temperature and stress fields of rub impact are calculated.Then the thermal-structure coupling numerical rubbing model and the motion equation are established.A numerical analysis method named as MATLAB is used to acquire the vibration characteristics,the vibration characteristics and the stability of the rotor in full annular rub with and without friction heat are calculated.The results are compared to get the law of friction heat effect of rub on dynamic characteristics of rotor in full annular rub.The specific research contents are summarized as follows:(1)The finite element model of rotor-to-stator rub system is established,and the structure analysis and thermal-structure coupling analysis are developed.The temperature and stress distributions of rotor and casing are obtained.It is found that friction heat increases the rubbing stress of the rotor and casing,and points out the cumulative effect of friction heat on the rotor and casing.(2)The nonlinear rotor-to-stator numerical model is established,the range of speed of synchronous full annular rub,the local temperature distribution at the rub point,the thermal deflection and vibration characteristic diagrams of rotor in synchronous full annular rub without and with friction heat effect are given.The influence of friction heat on rotor in synchronous full annular rub is revealed.It is found that the friction heat decreases the revolution of rotor into and out of the synchronous full annular rub,and decreases the stability of the system.While the rotor amplitude and the maximum rub impact is increased by friction heat.(3)The speed into reverse full annular rub,the thermal deflection and the vibration characteristics diagrams of rotor in reverse full annular rub without and with friction heat are given.The influence of friction heat on rotor in reverse full annular rub is revealed.It is found that the friction heat decreases the radial displacement and stability of rotor,increases the speed into reverse full annular rub and the amplitude of rotor.