Nonlinear dynamics and chaos of a multi-disk rotating shaft undergoing large deflection mounted on a moving support

摘要

ABSTR A C T In this work, the nonlinear dynamic responses of a high-speed rotor-bearing system have been investigated to explore the safe operating regions (SORs) with stable parametric shelter. Here, a new large deflection model of a high-speed multi-disk rotating shaft mounted on a moving base has been developed accounting for nonlinear geometric curvature and gyroscopic effect. Viscoelastic rotating shaft has been chosen to passively reduce the severity of the structural instability. Frequency response analysis has been studied to investigate the steady state responses and their stability and bifurcation. Further, stability diagrams have been established to forecast the route to chaos phenomena. It has been found that the present system losses its stability via S-N bifurcation while depending on parameter's value; system can undergo chaotic behaviour. Frequency responses curves and bifurcation diagrams have been validated by exploring the time histories, Poincare's section, and phase portraits. The behaviour of the present system can be successfully controlled with an appropriate selection of magnitude and frequency of base motion, loss-factor and number of rigid-disks. Outcomes from this work can enable significant theoretical understanding of forced vibration analyses which are of great practical importance to determine the operational stability and possibility of chaos occurrence.