Design of an adaptive–passive dynamic vibration absorber composed of a string–mass system equipped with negative stiffness tension adjusting mechanism

2013 ◽  
Vol 332 (2) ◽  
pp. 231-245 ◽  
Author(s):  
M.A. Acar ◽  
C. Yilmaz
Keyword(s):  
Negative Stiffness ◽  
Vibration Absorber ◽  
Dynamic Vibration Absorber ◽  
Mass System ◽  
Dynamic Vibration

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.

Theory for an Active Dynamic Vibration Absorber

1991 ◽  
Author(s):  
L. S. Stephens ◽  
K. E. Rouch ◽  
S. G. Tewani
Keyword(s):  
Closed Form Solution ◽  
Control Element ◽  
Vibrational Amplitude ◽  
Vibration Absorber ◽  
Vibration Absorbers ◽  
Lumped Mass ◽  
Dynamic Vibration Absorber ◽  
Mass System ◽  
Dynamic Vibration ◽  
The Impact

Abstract Research in dynamic vibration absorbers has yielded several fundamental designs. Among these are the tuned dynamic absorber, the Lanchester damper, and the impact damper. These designs utilize certain combinations of passive mechanical elements (springs and dampers) to reduce the vibrational amplitude of a system. However, with recent advances in motion sensing and actuating, the design of vibration absorbers that utilize actively actuated elements has become more attractive. This paper develops the theory for using a damped dynamic vibration absorber with an active control element to reduce the vibrational amplitude of a lumped mass system. A control law consisting of a linear combination of velocity and acceleration of the main mass is developed for the active element A closed-form solution is presented for the absorber tuning equation, and numerical methods are used to generate performance curves.

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