Dynamic stability of a shaft-disk system with flaws

The dynamic stability behavior of a cantilever shaft-disk system with flaws and subjected to axial periodic forces is studied by the finite element method. In the present analysis the effects of translational and rotatory inertia, gyroscopic moments, bending and shear deformation have been taken into consideration. Four parameters are employed to characterize the damaged zone: location, size, effective bending and shear stiffness of the damaged region. Numerical results show that due to the presence of the damaged zone, the regions of dynamic instability are shifted closer to the dynamic load factor axis and parametric resonance may occur at lower disturbance frequencies. Also, as the rotational speed increases, the sizes of the regions of dynamic instability will be enlarged, and therefore, the system becomes more unstable.