Maximizing Damping Effect of the Vibration by Changing the Natural Frequency of Tuned Mass Damper

2019 ◽  
Vol 11 (1) ◽  
pp. 26-36
Author(s):  
Seongmin Hong ◽  
Bumjin Kim ◽  
Eun-Jeong Yu
Keyword(s):  
Natural Frequency ◽  
Tuned Mass Damper ◽  
Damping Effect ◽  
Mass Damper

On Vibration Suppression and Energy Dissipation Using Tuned Mass Particle Damper

2016 ◽  
Author(s):  
Shilong Li ◽  
J. Tang
Keyword(s):  
Primary Structure ◽  
Vibration Suppression ◽  
Tuned Mass Damper ◽  
Harsh Environment ◽  
Gravitational Acceleration ◽  
Mass Particle ◽  
Damping Effect ◽  
Numerical Studies ◽  
Mass Damper ◽  
Particle Damping

Particle damping has the promising potential for attenuating the unwanted vibrations in harsh environment. However, the damping performance of the conventional particle damper (PD) may be ineffective, especially when the acceleration of the particle damper is less than gravitational acceleration (1g). In order to improve the damping performance of the traditional PD, the tuned mass particle damper (TMPD) which utilizes the advantages of both the tuned mass damper and particle damper is investigated in this paper. The TMPD can act as the tuned mass damper to not only absorb the vibration of the primary structure but also amplify the motions of the particles in the enclosure, which will significantly enhance the particle damping effect. To analyze the damping effect of the TMPD, a new coupling method to integrate the TMPD into the continuous host structure is first developed. The 3D discrete element method is then adopted to accurately describe and analyze the motion of particles in the enclosure. Furthermore, the analysis is validated by correlating the numerical and experimental results. With the new method as basis, detailed numerical studies are further carried out to verify the damping effectiveness of the TMPD compared with conventional PD under various excitation levels. The results demonstrate that the TMPD can significantly improve the damping effect of the conventional PD on suppressing the vibration of the primary structure under both the low and high excitation levels.

An Analysis of a Tuned Mass Damper under Dynamic Loads

2018 ◽  
Vol 760 ◽  
pp. 272-277
Author(s):  
Vladimir Šána ◽  
Jiří Litoš ◽  
Zdeňka Říhová ◽  
Markéta Kočová
Keyword(s):  
Dynamic System ◽  
Natural Frequency ◽  
Tuned Mass Damper ◽  
System Structure ◽  
Time Dependent ◽  
Dynamic Loads ◽  
Mass Damper

The submitted paper is focused on the design of Tuned Mass Damper in order to reduce excessive level of vibration. This device is designed to be active at the first natural frequency of the structure. Subsequently, the efficiency of the new dynamic system (structure-TMD) is verified for several types of time-dependent loads, which express swaying vandal, jumping vandal and moving pedestrian.

scholarly journals On Vibration Suppression and Energy Dissipation Using Tuned Mass Particle Damper

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
Shilong Li ◽  
J. Tang
Keyword(s):  
Energy Dissipation ◽  
Vibration Suppression ◽  
Tuned Mass Damper ◽  
Integrated System ◽  
Mass Particle ◽  
Local Displacement ◽  
Damping Effect ◽  
Mass Damper ◽  
Particle Damping ◽  
Damping Materials

Particle damping has the promising potential for attenuating unwanted vibrations in harsh environments especially under high temperatures where conventional damping materials would not be functional. Nevertheless, a limitation of simple particle damper (PD) configuration is that the damping effect is insignificant if the local displacement/acceleration is low. In this research, we investigate the performance of a tuned mass particle damper (TMPD) in which the particle damping mechanism is integrated into a tuned mass damper (TMD) configuration. The essential idea is to combine the respective advantages of these two damping concepts and in particular to utilize the tuned mass damper configuration as a motion magnifier to amplify the energy dissipation capability of particle damper when the local displacement/acceleration of the host structure is low. We formulate a first-principle-based dynamic model of the integrated system and analyze the particle motion by using the discrete element method (DEM). We perform systematic parametric studies to elucidate the damping effect and energy dissipation mechanism of a TMPD. We demonstrate that a TMPD can provide significant vibration suppression capability, essentially outperforming conventional particle damper.

Mitigation of Vortex-Induced Vibrations of a Pivoted Circular Cylinder Using an Adaptive Pendulum Tuned-Mass Damper

2013 ◽  
Vol 135 (11) ◽  
Author(s):  
Sina Kheirkhah ◽  
Richard Lourenco ◽  
Serhiy Yarusevych ◽  
Sriram Narasimhan
Keyword(s):  
Frequency Response ◽  
Natural Frequency ◽  
Damping Ratio ◽  
Tuned Mass Damper ◽  
Single Frequency ◽  
Fundamental Frequencies ◽  
Transverse Vibrations ◽  
Synchronization Region ◽  
Vortex Induced Vibrations ◽  
Mass Damper

A novel adaptive pendulum tuned-mass damper (TMD) was integrated with a two degree-of-freedom (DOF) cylindrical structure in order to control vortex-induced vibrations of the structure. The natural frequency of the TMD was adjusted autonomously in order to control the vortex-induced vibrations. The experiments were performed at a constant Reynolds number of 2100 and for four reduced velocities, 4.18, 5.44, 6.00, and 6.48. Two TMD damping ratios, 0 and 0.24, were investigated for a constant TMD mass ratio of 0.087. The results demonstrate that tuning the natural frequency of the TMD to the natural frequency of the structure decreases the amplitudes of transverse and streamwise vibrations of the structure significantly. Specifically, the transverse amplitudes of vibrations are decreased by a factor of ten and streamwise amplitudes of vibrations are decreased by a factor of three. Depending on the value of the TMD damping ratio, the frequency of transverse vibrations is either characterized by the natural frequency of the structure or by two other fundamental frequencies, one higher and the other lower than the natural frequency of the structure. The results demonstrate that, independent of the TMD damping and tuning frequency ratios, the frequency of streamwise vibrations matches that of the transverse vibrations in the synchronization region, and the cylinder traces elliptic trajectories. A mathematical model is proposed to gain insight into the frequency response of the structure and fluid-structure interactions. The model shows that, for low TMD damping ratios, the frequency response of the structure equipped with the TMD is characterized by two fundamental frequencies; whereas, for relatively high TMD damping ratios, the frequency response of the structure is characterized by a single frequency, i.e., the natural frequency. In both cases, the fluid forcing within the synchronization region is linked to the fundamental frequency/frequencies of the structure. Thus, the classical definition of synchronization applies to multiple DOF structures undergoing vortex-induced vibrations.

Dynamic analysis of viscoelastic tuned mass damper system under harmonic excitation

2019 ◽  
Vol 25 (11) ◽  
pp. 1768-1779 ◽  
Author(s):  
Jun Dai ◽  
Zhao-Dong Xu ◽  
Pan-Pan Gai
Keyword(s):  
Frequency Dependence ◽  
Natural Frequency ◽  
Storage Modulus ◽  
Primary Structure ◽  
Loss Factor ◽  
Design Strategy ◽  
Tuned Mass Damper ◽  
Optimum Frequency ◽  
Mass Damper ◽  
And Control

The purpose of this paper is to investigate the contribution of viscoelastic material (VEM) to the control performance of the viscoelastic tuned mass damper (VTMD). Firstly, the equivalent fractional derivation Kelvin model is used to describe the frequency dependence of viscoelasticity in VTMD, and an index is proposed to characterize the level of frequency dependence. Then the effects of the high loss factor of VEM and frequency dependence of viscoelasticity on the effectiveness and robustness of VTMD control are analyzed by numerical examples. At last, a design strategy for VTMD is proposed to select the type of VEM and optimize its stiffness contribution. The results show that the frequency dependence of shear storage modulus of VEM is beneficial to further reduce the dynamic response of the primary structure equipped with VTMD, and the loss factor of VEM determines the optimum frequency ratio and control effect of VTMD. Compared to the conventional tuned mass damper, VTMD has a better robustness for the positive error of the natural frequency of VTMD but has a worse robustness for the negative error. The frequency dependence of shear storage modulus of VEM is beneficial to the robustness of VTMD for both the positive and negative errors of the natural frequency of the primary structure. The VEM with a strong frequency dependence of shear storage modulus is the ideal VEM for VTMD, and the proposed design strategy can deal with the trade-off between the control effectiveness and control robustness of VTMD.

Vibration Control Performance of Damping Coupled Tuned Mass Dampers

2004 ◽  
Author(s):  
Nobuo Masaki ◽  
Hisashi Hirata
Keyword(s):  
Vibration Control ◽  
Natural Frequency ◽  
Tuned Mass Damper ◽  
Control Performance ◽  
Tuned Mass Dampers ◽  
Mass Unit ◽  
Optimal Value ◽  
Mass Damper ◽  
Rubber Bearings ◽  
Prefabricated Houses

Recently tuned mass dampers have been installed on three-story prefabricated houses for reducing of traffic-induced vibration and improving living comfort. This tuned mass damper consists of a mass unit, spring units and laminated rubber bearings. The mass is supported by four laminated rubber bearings, and spring units are used for adjusting the natural frequency of the tuned mass damper to the optimal value. Vibration control performance of this type of tuned mass dampers is deteriorated when the natural frequency of the house is changed. To solve this problem, the authors have developed a damping coupled tuned mass damper. In this type of tuned mass damper, two mass units having slightly different natural frequencies are coupled by using a damping unit. In this paper, mechanism and vibration control performance of the damping coupled tuned mass damper are described.

Numerical and Experimental Study on Dynamic Response Mitigation of Tension Leg Platform Using Tuned Mass Damper

2021 ◽  
pp. 1-12
Author(s):  
Mohammad Reza Tabeshpour ◽  
Latif Nikmehr
Keyword(s):  
Natural Frequency ◽  
Experimental Studies ◽  
Tuned Mass Damper ◽  
Offshore Structures ◽  
Response Amplitude ◽  
Structural Safety ◽  
Wave Load ◽  
Tension Leg Platform ◽  
Stable Conditions ◽  
Mass Damper

Response amplitude mitigation of the offshore structures like tension leg platform (TLP) is important since these structures are always exposed to environmental loads such as waves, and in the case of TLP, reduction in response amplitude of platform causes reduction in stress range in tendons; this would increase the fatigue life of tendons, and therefore, increases the structural safety. Also providing stable conditions for machinery and crew increases the efficiency and functionality of the platform. This article thus aims to investigate the possibility and effectiveness of applying tuned mass damper (TMD) as a passive structural control system to suppress the surge motion of TLP that is exposed to wave load. Both numerical and experimental studies were carried out to assess the performance of the TMD. A close agreement is obtained between the numerical simulations and experimental results. The results of numerical and experimental investigations in this study indicate that applying the TMD, tuned to the surge natural frequency of the platform or frequencies close to the surge natural frequency of the platform, doesn’t have efficiency in reducing the surge responses of TLP in the range of probable waves in seas and oceans.

Tuned mass damper and high static low dynamic stiffness isolator for vibration reduction of beam structure

2019 ◽  
Vol 234 (1) ◽  
pp. 95-115 ◽  
Author(s):  
Meysam Raei ◽  
Morteza Dardel
Keyword(s):  
Natural Frequency ◽  
Dynamic Stiffness ◽  
Excitation Amplitude ◽  
Tuned Mass Damper ◽  
Degree Of Freedom ◽  
Negative Stiffness ◽  
Low Frequencies ◽  
First Case ◽  
Mass Damper ◽  
Two Degree Of Freedom

In this work, the combination effect of tuned mass damper and high static low dynamic stiffness (HSLDS) isolator is investigated in reducing the vibration amplitude of Euler–Bernoulli beam with a nonlinear attachment. The performance of the absorber is studied in two cases; the first case, HSLDS isolator is one degree of freedom and the second case, two degree of freedom isolator is combined of HSLDS isolator and tuned mass damper absorber. By comparing the performance of these two isolators, it is revealed the two degree of freedom isolator has much better performance in direct force excitation and also improves the system performance in the base excitation. This isolator reduces the system amplitude at all frequencies, especially ultra-low frequencies, which is the main advantage to this isolator with respect to other isolators and reduces the natural frequency until the phenomenon of resonance occurs at a lower frequency. Moreover, decreasing the natural frequency increases the damping and in quasi zero stiffness and negative stiffness structure, the system has supercritical damping. This isolator is studied for positive, quasi zero and negative stiffness. The results show that the system with quasi zero stiffness has the best performances. Also, by increasing the excitation amplitude, the isolator loses its effectiveness.

Damping Effect of Pendulum Tuned Mass Damper on Vibration of Two-Dimensional Rigid Body

2015 ◽  
Vol 15 (02) ◽  
pp. 1450041 ◽  
Author(s):  
Yi-Ren Wang ◽  
Ko-En Hung
Keyword(s):  
Rigid Body ◽  
Internal Resonance ◽  
Multiple Scales ◽  
Tuned Mass Damper ◽  
Contour Plot ◽  
Main Body ◽  
Two Dimensional ◽  
Damping Effect ◽  
Eigen Analysis ◽  
Mass Damper

This study investigated the effect of a pendulum tuned mass damper (PTMD) on the vibration of a slender two-dimensional (2D) rigid body with 1:2 internal resonance. Focus is placed on the damping effect of various parameters of the PTMD on preventing the internal resonance of the system. The instruments used include fixed points plots, time response and Poincaré maps, which were compared for confirmation of accuracy. The Lagrange's equation is employed to derive the equations of motion for the system. The method of multiple scales (MOMS) is applied to analyzing this nonlinear vibration model. The internal resonance conditions of the rigid body in vibration are obtained by the eigen-analysis. Moreover, a 3D internal resonance contour plot (3D-IRCP) aided by various amplitude analysis tables is proposed for identification of the parameter combinations of the PTMD for preventing internal resonance. This approach enables the designers to evaluate the effectiveness of various parameter combinations of the PTMD prior to the design process. The present study indicates that without changing the main configuration, the vibration amplitudes in the main body can be greatly reduced under certain parameter combinations of the PTMD.

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