Nonlinear dynamics analysis of shaft crack

Considering the “breathing” phenomenon of cracks in a rotor system as the shaft rotates, this study derives the true breathing formula for shaft cracks, adopts more realistic flexural and torsional stiffnesses of the cracked shaft segments, and establishes a time-varying stiffness matrix for the cracked shaft. Sub-se-quently, a finite element dynamics model of the gear transmission system con-taining gear-shaft-bearing is established to elucidate the dynamic charac-teristics of the system affected by the shaft crack. The dynamic characteristics of the sys-tem under the influence of shaft cracks are analyzed by changing the crack pa-rameters such as different crack depths and different numbers of cracks.