Influence of Crack Nonlinear Breathing Behavioron the Critical Speed of the Rotor
CHENG Li1,2; HE Zheng-jia1; LI Ning2; CHEN Xue-feng1; DONG Hong-bo1
1. State Key Laboratory for Manufacturing systems Engineering, Xi’an Jiaotong University, Xi’an 710049,China;2. Air Force Engineering University ,Xi’an 710038,China
Abstract：The general motion equations of a Jeffcott rotor with a transverse crack were developed for studying the influence of crack nonlinear breathing behavior due to whirling on the critical speed of the rotor, in which the complicated manner of rotor’s whirl is considered. By the new equations, the numerical results and analysis for the steady vibration response of cracked rotor near the critical speed show that the nonlinear breathing behavior not only can strengthen the stability of rotor (compared with the opening cracked rotor), but also can reduce the vibration response in certain conditions (compared with the un-cracked rotor).The stability cracked rotor is same as un-cracked rotor. When the rotation speed coincides with the critical speed, the vibration response is maximum and the center of gravity rotates about . The critical speed is a function of the imbalance orientation angle, varying between the natural frequency of rotor with crack opening and closing. The passage through critical speed experimental observations of cracked rotor on a rotor test rig support the analytical results.
2010, Vol. 29 
