Vibration-based crack diagnosis in rotating shafts during acceleration through resonance

摘要

The dynamic response of a cracked Jeffcott rotor passing through the critical speed with constant acceleration is investigated analytically and numerically. The nonlinear equations of motion are derived and include a simple hinge model for small cracks and Mayesu27 modified funciton for deep cracks. The equations of motion are integrated in the rotating coordinate system. The angle between the crack centerline and the shaft vibaiton (whirl) vector is used to determine the clsoing and opening of the crack, allowing one to study the dynamic response with and without the rotor weight dominance. Vibration phase response is used as one of possible tools for detection the existence of cracks. The results of parametric studies of the effect of crack depth, unbalance eccentricity orientation with respect to crack, and the rotor acceleration on the rotoru27s response are presented.