Showing papers by "A. S. Sekhar published in 2000"
TL;DR: In this paper, the stability threshold of a rotor bearing system having a transverse crack has been studied by using FEM and considering the various crack parameters and shaft internal damping (viscous and hysteretic damping) and geometric parameters.
46 citations
TL;DR: In this article, a non-linear transient stability analysis of a rigid rotor supported on two symmetric hydrodynamic bearings with rough surfaces subjected to a unidirectional constant load was performed.
Abstract: Non-linear transient stability analysis has been performed to study the sub-synchronous whirl stability of a rigid rotor supported on two symmetric hydrodynamic bearings with rough surfaces subjected to a unidirectional constant load. A Reynolds type equation for finite hydrodynamic bearings, with different models of rough surfaces, has been solved using the stochastic finite element method. The trajectories of the journal center have been obtained by solving the equations of motion of the journal center by the fourth-order Runge-Kutta method. Results show an increase in the stability with transverse roughness and a decrease in the stability with isotropic roughness. A small improvement in stability is obtained with longitudinal roughness.
8 citations
01 Jul 2000
TL;DR: In this article, the effects of fluid film bearings on cracks in a cracked Jeffcott rotor have been analyzed, in addition to the Q factors and dissipation coefficients of the rotor.
Abstract: Dynamic analysis of a cracked Jeffcott rotor has been carried out, considering the effects of fluid film bearings. Q factors and dissipation coefficients have been evaluated in addition to the harmonic responses of the rotor. The coast down phenomenon was analysed for the effects of crack depth. Sensitivity studies were carried out, considering dissipation, response and the Q factor. Measurement of Q factors of second harmonics, Qx1 and Qy2, has been suggested for crack detection, while measurement of Q factors of first harmonics is recommended for crack monitoring as these proved to be more sensitive to cracks compared with other methods.
6 citations