Vibration attenuation using a nonlinear dynamic vibration absorber with negative stiffness

2019 ◽  
Vol 59 (2) ◽  
pp. 617-628
Author(s):  
Guangxu Dong ◽  
Qiang Li ◽  
Xinong Zhang
Keyword(s):  
Nonlinear Dynamic ◽  
Negative Stiffness ◽  
Vibration Absorber ◽  
Dynamic Vibration Absorber ◽  
Dynamic Vibration ◽  
Vibration Attenuation

Controlling the vibration and noise of a ballasted track using a dynamic vibration absorber with negative stiffness

2019 ◽  
Vol 234 (10) ◽  
pp. 1265-1274
Author(s):  
Haiping Liu ◽  
Dongmei Zhu
Keyword(s):  
Decay Rate ◽  
Negative Stiffness ◽  
Design Parameters ◽  
Vibration Energy ◽  
Vibration Absorber ◽  
Dynamic Vibration Absorber ◽  
Radiated Noise ◽  
Dynamic Vibration ◽  
Track System ◽  
Ballasted Track

In this study, a rail dynamic vibration absorber with negative stiffness is developed to reduce the vibration transmission and radiated noise from the rail components of a ballasted track. The compound models of the ballasted track system with and without the proposed dynamic vibration absorber and a traditional dynamic vibration absorber are constructed. A parametric study is performed to evaluate the effects of the design parameters of the proposed dynamic vibration absorber on the vibration and noise reduction of the track system in terms of the point receptance, the decay rate of rail vibration along the track, and the vibration energy level of the rail. Compared with the traditional dynamic vibration absorber, the proposed counterpart can work effectively over a broad frequency range around resonance. The efficiency of the dynamic vibration absorber can be improved by adjusting the design values of the active mass and damping coefficient. A comparison with the traditional dynamic vibration absorber shows that the vibration and noise suppression capability of the proposed one can be enhanced by increasing the value of the stiffness ratio. However, different from the traditional dynamic vibration absorber, the design parameters of the proposed one can also affect the decay rate and vibration energy at low-frequency regions. A discrete track with the proposed dynamic vibration absorber, which is arranged in continuous or discrete distribution along the rail, is illustrated to study the influences of the rail components on the decay rate and vibration energy level of rails. These calculated results could provide a theoretical basis for the design of the proposed dynamic vibration absorber in controlling the vibration and radiated noise from rails.

Principle, modeling, and control of a magnetorheological elastomer dynamic vibration absorber for powertrain mount systems of automobiles

2016 ◽  
Vol 28 (16) ◽  
pp. 2239-2254 ◽  
Author(s):  
Fu-Long Xin ◽  
Xian-Xu Bai ◽  
Li-Jun Qian
Keyword(s):  
Frequency Shift ◽  
Vibration Isolation ◽  
Vibration Absorber ◽  
Magnetorheological Elastomer ◽  
Dynamic Vibration Absorber ◽  
Vibration Absorption ◽  
Dynamic Vibration ◽  
Passive Vibration Isolation ◽  
Vibration Attenuation ◽  
Vibration Attenuation Performance

This article proposes and validates the principle of a new magnetorheological elastomer (MRE) dynamic vibration absorber (DVA) for powertrain mount systems of automobiles. The MRE DVA consists of a vibration absorption unit and a passive vibration isolation unit. The vibration absorption unit composed of a magnetic conductor, a shearing sleeve, a bobbin core, an electromagnetic coil, and a circular cylindrical MRE is utilized to absorb the vibration energy, and the passive vibration isolation unit is used to support the powertrain. The finite element method is employed to validate the electromagnetic circuit of the MRE DVA and obtain the electromagnetic characteristics. The theoretical frequency-shift principle is analyzed via the established constitutive equations of the circular cylindrical MRE In order to demonstrate how the parameters of the MRE influence the vibration attenuation performance, the MRE DVA is applied to a powertrain mount system to replace the conventional passive mount. The frequency-shift property of the vibration absorption unit and the vibration attenuation performance of the MRE DVA on the powertrain mount system are experimentally tested. To validate and improve the vibration attenuation performance for the semi-active powertrain mount systems, an optimal variable step algorithm is proposed for the MRE DVA and numerical experiments are carried out.

Research of a Dynamic Vibration Absorber with Tunable Resonant Frequency and its Vibration Attenuation Characteristics

2014 ◽  
Vol 511-512 ◽  
pp. 601-605
Author(s):  
Qiang Ma ◽  
Jie Jian Di ◽  
Xiao Wu Du ◽  
Quan Liang Zhao
Keyword(s):  
Resonant Frequency ◽  
Frequency Band ◽  
Vibration Absorber ◽  
Geometrical Parameters ◽  
Dynamic Vibration Absorber ◽  
Damping Effect ◽  
Dynamic Vibration ◽  
Vibration Attenuation ◽  
Working Frequency ◽  
Attenuation Characteristics

In order to improve working frequency band and damping effect of a dynamic vibration absorber, a new kind of dynamic vibration absorber is presented. Its resonant frequency could be real-time adjusted by adapting the stiffness of the spring. The vibration attenuation characteristics are analyzed theoretically and numerically. According to simulation analysis, effects of geometrical parameters are researched and optimum geometric parameters are determined. The damping effect was simulated in a flat structure, the results show that the working frequency band and damping effect of the DVA are both remarkable.

scholarly journals Robust Optimal Design of a Nonlinear Dynamic Vibration Absorber Combining Sensitivity Analysis

2010 ◽  
Vol 17 (4-5) ◽  
pp. 507-520 ◽  
Author(s):  
R.A. Borges ◽  
A.M.G. de Lima ◽  
V. Steffen Jr.
Keyword(s):  
Sensitivity Analysis ◽  
Optimal Design ◽  
Nonlinear Dynamic ◽  
Vibration Absorber ◽  
Vibration Absorbers ◽  
Optimization Strategy ◽  
Dynamic Vibration Absorber ◽  
Dynamic Vibration ◽  
Robust Optimal Design ◽  
Dynamic Vibration Absorbers

Dynamic vibration absorbers are discrete devices developed in the beginning of the last century used to attenuate the vibrations of different engineering structures. They have been used in several engineering applications, such as ships, power lines, aeronautic structures, civil engineering constructions subjected to seismic induced excitations, compressor systems, etc. However, in the context of nonlinear dynamics, few works have been proposed regarding the robust optimal design of nonlinear dynamic vibration absorbers. In this paper, a robust optimization strategy combined with sensitivity analysis of systems incorporating nonlinear dynamic vibration absorbers is proposed. Although sensitivity analysis is a well known numerical technique, the main contribution intended for this study is its extension to nonlinear systems. Due to the numerical procedure used to solve the nonlinear equations, the sensitivities addressed herein are computed from the first-order finite-difference approximations. With the aim of increasing the efficiency of the nonlinear dynamic absorber into a frequency band of interest, and to augment the robustness of the optimal design, a robust optimization strategy combined with the previous sensitivities is addressed. After presenting the underlying theoretical foundations, the proposed robust design methodology is performed for a two degree-of-freedom system incorporating a nonlinear dynamic vibration absorber. Based on the obtained results, the usefulness of the proposed methodology is highlighted.

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