scholarly journals Dynamic Vibration Absorber with Negative Stiffness for Rotor System

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Hongliang Yao ◽  
Zidong Chen ◽  
Bangchun Wen
Keyword(s):  
Permanent Magnets ◽  
Vibration Suppression ◽  
Rotor System ◽  
Negative Stiffness ◽  
Vibration Absorber ◽  
Dynamic Vibration Absorber ◽  
Suppression Effect ◽  
System A ◽  
Control Frequency ◽  
Nonlinear Dynamic Characteristics

To suppress the vibration of a rotor system, a vibration absorber combining negative stiffness with positive stiffness together is proposed in this paper. Firstly, the negative stiffness producing mechanism using ring type permanent magnets is presented and the characteristics of the negative stiffness are analyzed. Then, the structure of the absorber is proposed; the principles and nonlinear dynamic characteristics of the absorber-rotor system are studied numerically. Finally, experiments are carried out to verify the numerical conclusions. The results show that the proposed vibration absorber is effective to suppress the vibration of the rotor system, the nonlinearity of the negatives stiffness affects the vibration suppression effect little, and the negative stiffness can broaden the effective vibration control frequency range of the absorber.

Design and vibration suppression performance of magnetic suspension dynamic vibration absorber

2020 ◽  
pp. 107754632096089
Author(s):  
Chaowu Jin ◽  
Yue Dong ◽  
Xudong Guan ◽  
Jin Zhou ◽  
Fan Wang
Keyword(s):  
Frequency Band ◽  
Vibration Suppression ◽  
Fixed Point Theory ◽  
Magnetic Suspension ◽  
Vibration Absorber ◽  
Dynamic Vibration Absorber ◽  
Modal Frequency ◽  
Suppression Effect ◽  
Dynamic Vibration ◽  
Main System

In this article, a magnetic suspension technique was introduced into the field of vibration absorption. Using the advantage of adjustable control parameters of a magnetic suspension system, a type of a magnetic suspension dynamic vibration absorber that can achieve broadband vibration suppression was designed. First, the theoretical model of a magnetic suspension dynamic vibration absorber was established. Then, the cantilever beam with sinusoidal excitation is seen as the main system of vibration suppression; combined with the fixed point theory (Seto K (2013) Dynamic Vibration Absorber and its Application. Mechanic Industry Press), the specific structure of the magnetic suspension dynamic vibration absorber was designed. Based on that, the simulation study of vibration suppression performance of the magnetic suspension dynamic vibration absorber was carried out. The results indicated that the vibration of the main system at the 1st modal frequency was reduced by 65.38% under the action of the magnetic suspension dynamic vibration absorber, compared with that without the action of the magnetic suspension dynamic vibration absorber. Furthermore, the vibration of the main system can be suppressed in the frequency band of [16 Hz, 32 Hz]. Finally, a vibration test rig of the magnetic suspension dynamic vibration absorber was built up for experimental study. And the results showed that the absorber can decrease the vibration of the main system by 43.03% at the 1st modal frequency compared with that without the action of magnetic suspension dynamic vibration absorber and had a certain suppression effect (decrease varies from 0 to 43.03%) on the vibration of the main system in the frequency band of [20 Hz, 32 Hz].

scholarly journals Influence of radial clearance on nonlinear dynamics of a two-span three-support rotor system

2021 ◽  
Vol 233 ◽  
pp. 04012
Author(s):  
HE Xing ◽  
WU Yi-ming ◽  
LI Mo ◽  
ZENG Fan
Keyword(s):  
Periodic Motion ◽  
Rotor System ◽  
System Model ◽  
Radial Clearance ◽  
Structural Form ◽  
Single Cycle ◽  
Rolling Bearings ◽  
System A ◽  
Runge Kutta Method ◽  
Nonlinear Dynamic Characteristics

Aiming at the structural form of a certain rotor system, a double-span three-support rotor system model is established. It is supported by three rolling bearings and has a typical nonlinear characteristic. The fourth-order Runge-Kutta method is used to solve the differential equations and analyze the nonlinear dynamic characteristics of the rotor system when the radial clearance of the bearing changed. The research results: with the increase of the rear bearing radial clearance, the rotor system performs single cycle, periodic two and pseudo-periodic motion. With the three location bearing radial clearance increases, the rotor system performs single cycle, periodic two and periodic four motion. When the radial clearance is bigger, the rotor system performs two periodic motion. The influence law of radial clearance on double span three - braced rotor system is shown.

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.

scholarly journals Design and Experimental Implementation of a Beam-Type Twin Dynamic Vibration Absorber for a Cantilevered Flexible Structure Carrying an Unbalanced Rotor: Numerical and Experimental Observations

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Abdullah Özer ◽  
Mojtaba Ghodsi ◽  
Akio Sekiguchi ◽  
Ashraf Saleem ◽  
Mohammed Nasser Al-Sabari
Keyword(s):  
Rotor System ◽  
Operating Conditions ◽  
System Response ◽  
Flexible Structure ◽  
Vibration Absorber ◽  
Dynamic Vibration Absorber ◽  
Element Analysis ◽  
Dynamic Vibration ◽  
Unbalanced Rotor ◽  
Beam Type

This paper presents experimental and numerical results about the effectiveness of a beam-type twin dynamic vibration absorber for a cantilevered flexible structure carrying an unbalanced rotor. An experimental laboratory prototype setup has been built and implemented in our laboratory and numerical investigations have been performed through finite element analysis. The proposed system design consists of a primary cantilevered flexible structure with an attached dual-mass cantilevered secondary dynamic vibration absorber arrangement. In addition, an unbalanced rotor system is attached to the tip of the flexible cantilevered structure to inspect the system response under harmonic excitations. Numerical findings and experimental observations have revealed that significant vibration reductions are possible with the proposed dual-mass, cantilevered dynamic vibration absorber on a flexible cantilevered platform carrying an unbalanced rotor system at its tip. The proposed system is efficient and it can be practically tuned for variety of design and operating conditions. The designed setup and the results in this paper can serve for practicing engineers, researchers and can be used for educational purposes.

scholarly journals Optimal parameters of dynamic vibration absorber for linear damped rotary systems subjected to harmonic excitation

2020 ◽  
Author(s):  
Vu Duc Phuc ◽  
Tong Van Canh ◽  
Pham Van Lieu
Keyword(s):  
Vibration Suppression ◽  
Fixed Point Theory ◽  
Damping Ratio ◽  
Harmonic Excitation ◽  
Tuning Parameter ◽  
Vibration Absorber ◽  
Optimal Parameters ◽  
Dynamic Vibration Absorber ◽  
Practical Applications ◽  
Dynamic Vibration

Dynamic vibration absorber (DVA) is a simple and effective device for vibration absorption used in many practical applications. Determination of suitable parameters for DVA is of significant importance to achieve high vibration reduction effectiveness. This paper presents a   method to find the optimal parameters of a DVA attached to a linear damped rotary system excited by harmonic torque. To this end, a closed-form formula for the optimum tuning parameter is derived using the fixed-point theory based on an assumption that the damped rotary systems are lightly or moderately damped. The optimal damping ratio of DVA is found by solving a set of non-linear equations established by the Chebyshev's min-max criterion. The performance of the proposed optimal DVA is compared with that obtained by existing optimal solution in literature. It is shown that the proposed optimal parameters are possible to obtain superior vibration suppression compared to existing optimal formula. Extended simulations are carried out to examine the performance of the optimally designed DVA and the sensitivity of the optimum parameters. The simulation results show that the improvement of the vibration performance on damped rotary system can be as much as 90% by using DVA.

Study on the vibration suppression of a flexible carbody for urban railway vehicles with a magnetorheological elastomer-based dynamic vibration absorber

2019 ◽  
Vol 234 (7) ◽  
pp. 749-764 ◽  
Author(s):  
Yongpeng Wen ◽  
Qian Sun ◽  
Yu Zou ◽  
Haoming You
Keyword(s):  
Vibration Suppression ◽  
Design Method ◽  
Elastic Vibration ◽  
Parameter Determination ◽  
Railway Vehicle ◽  
Vibration Absorber ◽  
Magnetorheological Elastomer ◽  
Dynamic Vibration Absorber ◽  
Optimum Frequency ◽  
Dynamic Vibration

Magnetorheological elastomer is a new kind of intelligent material that mainly incorporates micron-sized ferromagnetic particles into a polymer. A dynamic vibration absorber that is based on the controllable shear modulus of magnetorheological elastomer is widely used in vibration systems. In the study, a flexible carbody model with a magnetorheological elastomer dynamic vibration absorber is established. A design method of a semiactive dynamic vibration absorber that is based on magnetorheological elastomer is introduced, and the operational principle of the semiactive dynamic vibration absorber is also discussed. To improve the vibration absorption performance of the magnetorheological elastomer dynamic vibration absorber, via multiple regression analysis, the optimal design frequency expressions for both the rigid vibration and the elastic vibration of the carbody are fitted. Parameter determination for the magnetorheological elastomer dynamic vibration absorber is investigated in detail. Then, the effects on the rigid vibration and the elastic vibration with the magnetorheological elastomer vibration absorber both with the passive vibration absorber and without a vibration absorber are analyzed. Finally, Sperling’s riding index is used to evaluate the feasibility and the performance of the magnetorheological elastomer dynamic vibration absorber in a practical application. The results demonstrate that the vibration of the carbody can be effectively reduced by using the magnetorheological elastomer dynamic vibration absorber instead of the dynamic vibration absorber without the magnetorheological elastomer. The magnetorheological elastomer dynamic vibration absorber that is modified by the optimum frequency provides superior vibration reduction performance and improves the riding quality of the railway vehicle.

149 Vibration Suppression of Tilted Vibration System by Dynamic Vibration Absorber with Two Rollers

2004 ◽  
Vol 2004 (0) ◽  
pp. _149-1_-_149-6_
Author(s):  
Yilin SONG ◽  
Hidenori SATO ◽  
Yoshio IWATA ◽  
Toshihiko KOMATSZAKI ◽  
Yoshiyuki KISHIMOTO
Keyword(s):  
Vibration Suppression ◽  
Vibration Absorber ◽  
Vibration System ◽  
Dynamic Vibration Absorber ◽  
Dynamic Vibration
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