Showing papers by "A. S. Sekhar published in 1999"
TL;DR: In this article, Finite Element analysis of a rotor system for flexural vibrations has been considered by including a shaft with two open cracks and the influence of one crack over the other for eigenfrequencies, mode shapes and for threshold speed limits has been observed.
123 citations
TL;DR: In this paper, the influence of the roughness parameter (C) and roughness patterns (longitudinal, transverse and isotropic) on the steady state and dynamic characteristics of hydrodynamic journal bearings with rough surfaces has been studied using the model of Christensen and Tonder.
47 citations
TL;DR: In this article, a rotor system having a slant crack which occurs because of the fatigue of the shaft due to the torsional moment has been studied, and the frequency spectra of the steady state responses of the cracked rotor were found to have sub harmonic frequency components at an interval frequency corresponding to torsion frequency, which can be used for crack detection and monitoring.
Abstract: Detection and condition monitoring of a rotor system having a slant crack which occurs because of the fatigue of the shaft due to the torsional moment has been studied. Finite Element (FEM) analysis has been done for flexural vibrations by developing the stiffness matrix of a slant cracked element. Parametric study for eigen values and response has been performed with crack parameters VIZ, crack depth & location and operating and torsional frequencies. The frequency spectra of the steady state responses of the cracked rotor were found to have sub harmonic frequency components at an interval frequency corresponding to torsional frequency, which can be used for crack detection and monitoring.
9 citations
01 Jan 1999
TL;DR: In this article, the unbalance response and stability of a flexible rotor supported on hydrodynamic journal bearings with rough surfaces have been investigated, and the influence of the surface roughness patterns on the stability of the rotor has been evaluated.
Abstract: In this investigation the unbalance response and stability of a flexible rotor supported on hydrodynamic journal bearings with rough surfaces have been studied. The influence of the surface roughness patterns on the unbalance response and the stability of a rotor have been evaluated.
7 citations
TL;DR: In this article, the subsynchronous whirl stability limit of a rigid rotor supported on two symmetrical finite journal bearings has been studied using the linearised perturbation method and the nonlinear transient analysis technique.
Abstract: The subsynchronous whirl stability limit of a rigid rotor supported on two symmetrical finite journal bearings has been studied using the linearised perturbation method and the nonlinear transient analysis technique. A quantitative comparison for journal bearings with different l/d ratios has been provided.
7 citations
12 Sep 1999
1 citations