Support Parameters Design of Jeffcott Rotor using Nonlinear Energy Sink & H∞ Method

Document Type : Research Article

Authors

1 Faculty of Mechanical Engineering, Malayer University, Malayer, Iran

2 Faculty of Mechanical & Energy Engineering, Shahid Beheshti University, Tehran, Iran

10.22060/ajme.2020.17847.5876

Abstract

Rotating machinery support design with the aim of robustly absorbing transient disturbances over a broad range of frequencies has significant importance regarding the various applications of these machinery. Hence, the Nonlinear Energy Sink (NES) may be regarded as an efficient passive absorber, possessing adaptivity to the frequency content of vibrations of the primary system. This paper studies the effect of a nonlinear energy sinks on the vibration suppression of a flexible rotor-bearing supported by a linear damping and an essentially nonlinear stiffness. First, the governing equations for the Jeffcott rotor model mounted on flexible supports are derived and numerically solved. Then, the optimal parameters for the linear supports have been analytically achieved by H∞ optimization procedure. Furthermore, based on these analytical results, numerical simulations have been performed to optimize the NES parameters in order to obtain the optimum performance for vibration reduction. The approach method of the tuned damper support system is similar to that designed for dynamic vibration absorber optimization. The H∞ optimum parameters such as tuning frequency and damping ratios are expressed based on fixed-point theory to minimize the rotor amplitudes. It is proven by numerical simulations that the system optimization design can effectively improve the synchronous unbalance response. Additionally, the application of the NES is compared with that of the tuned mass damper (TMD).

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