Series-Type Pendulum Tuned Mass Damper-Tuned Sloshing Damper

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
J. S. Love ◽  
K. P. McNamara ◽  
M. J. Tait ◽  
T. C. Haskett
Keyword(s):  
Natural Frequency ◽  
Analytical Study ◽  
Linear Structure ◽  
Cost Effective ◽  
Tuned Mass Damper ◽  
Restoring Force ◽  
Equivalent Mechanical Model ◽  
Mass Damper ◽  
Series Type ◽  
Structural Motion

Abstract A pendulum-type tuned mass damper (TMD)-tuned sloshing damper (TSD) system is proposed as a cost-effective device to reduce wind-induced structural motion. Lagrange's principle is employed to develop an equivalent mechanical model for the system. The sloshing liquid provides additional gravitational restoring force to the pendulum TMD but does not provide a corresponding increase to its inertia. As a result, the natural frequency of the pendulum TMD is increased due to the TSD degree-of-freedom. Shake table testing is conducted on several pendulum TMD-TSD systems that are subjected to harmonic base excitation at discrete frequencies near the natural frequency of the pendulum TMD. The modeled and experimental results are in reasonable agreement when the liquid is not shallow or the response amplitude is not large. The pendulum TMD-TSD is coupled to a linear structure, and it is demonstrated through an analytical study that the device provides performance that is comparable to a traditional TMD. The proposed system is advantageous because it does not require a viscous damping system that is often one of the most costly components of traditional TMDs.

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.

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.

scholarly journals Wind Induced Vibration Control and Energy Harvesting of Electromagnetic Resonant Shunt Tuned Mass-Damper-Inerter for Building Structures

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Yifan Luo ◽  
Hongxin Sun ◽  
Xiuyong Wang ◽  
Lei Zuo ◽  
Ning Chen
Keyword(s):  
Energy Harvesting ◽  
Time Domain ◽  
Damping Ratio ◽  
Tuned Mass Damper ◽  
Structure Damage ◽  
Tuning Ratio ◽  
Mass Damper ◽  
Double Mass ◽  
Series Type ◽  
Resonant Shunt

This paper proposes a novel inerter-based dynamic vibration absorber, namely, electromagnetic resonant shunt tuned mass-damper-inerter (ERS-TMDI). To obtain the performances of the ERS-TMDI, the combined ERS-TMDI and a single degree of freedom system are introduced. H2 criteria performances of the ERS-TMDI are introduced in comparison with the classical tuned mass-damper (TMD), the electromagnetic resonant shunt series TMDs (ERS-TMDs), and series-type double-mass TMDs with the aim to minimize structure damage and simultaneously harvest energy under random wind excitation. The closed form solutions, including the mechanical tuning ratio, the electrical damping ratio, the electrical tuning ratio, and the electromagnetic mechanical coupling coefficient, are obtained. It is shown that the ERS-TMDI is superior to the classical TMD, ERS-TMDs, and series-type double-mass TMDs systems for protection from structure damage. Meanwhile, in the time domain, a case study of Taipei 101 tower is presented to demonstrate the dual functions of vibration suppression and energy harvesting based on the simulation fluctuating wind series, which is generated by the inverse fast Fourier transform method. The effectiveness and robustness of ERS-TMDI in the frequency and time domain are illustrated.

scholarly journals Experimental Study on Vibration Control of Suspended Piping System by Single-Sided Pounding Tuned Mass Damper

2019 ◽  
Vol 9 (2) ◽  
pp. 285 ◽  
Author(s):  
Jie Tan ◽  
Siu Michael Ho ◽  
Peng Zhang ◽  
Jinwei Jiang
Keyword(s):  
Free Vibration ◽  
Forced Vibration ◽  
Cost Effective ◽  
Tuned Mass Damper ◽  
Spring Steel ◽  
Piping System ◽  
Mass Damper ◽  
Piping Systems ◽  
High Flexibility ◽  
The Impact

Suspended piping systems often suffer from severe damages when subjected to seismic excitation. Due to the high flexibility of the piping systems, reducing their displacement is important for the prevention of damage during times of disaster. A solution to protecting piping systems during heavy excitation is the use of the emerging pounding tuned mass damper (PTMD) technology. In particular, the single-sided PTMD combines the advantages of the tuned mass damper (TMD) and the impact damper, including the benefits of a simple design and rapid, efficient energy dissipation. In this paper, two single-sided PTMDs (spring steel-type PTMD and simple pendulum-type PTMD) were designed and fabricated. The dampers were tested and compared with the traditional TMD for mitigating free vibration and forced vibration. In the free vibration experiment, both PTMDs suppressed vibrations much faster than the TMD. For the forced vibration test, the frequency response of the piping system was obtained for three conditions: without control, with TMD control, and with PTMD control. These novel results demonstrate that the single-sided PTMD is a cost-effective method for efficiently and passively mitigating the vibration of suspended piping systems. Thus, the single-sided PTMD will be an important tool for increasing the resilience of structures as well as for improving the safety of their occupants.

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.

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