The Multi-Degree-of-Freedom Tuned-Mass Damper for Suppression of Single-Mode Vibration Under Random and Harmonic Excitation

Author(s):  
Lei Zuo ◽  
Samir A. Nayfeh

Whenever a tuned-mass damper is attached to a primary system, there is potential for utilization of motion of the absorber body in more than one degree of freedom relative to the primary system. In this paper, we propose that more than one mode of vibration of an absorber body relative to a primary system be tuned to a single natural frequency of the primary system. We cast the problem of optimizing the multi-degree-of-freedom connection between the absorber body and primary structure as a decentralized control problem, and develop optimization algorithms based on the H2 and H-infinity norms to minimize the response to random and harmonic excitations, respectively. We find that a two-DOF absorber can attain better performance than the optimal SDOF absorber, even for the case where the rotary inertia of the absorber tends to be zero. With properly chosen connection locations, the two-DOF absorber can achieve better vibration suppression than two separate absorbers of optimized mass distribution. We also find that a two-DOF absorber with negative dampers in some of the connections to the primary system can obtain much better performance than absorbers with only positive dampers.

2005 ◽  
Vol 128 (1) ◽  
pp. 56-65 ◽  
Author(s):  
Lei Zuo ◽  
Samir A. Nayfeh

Whenever a tuned-mass damper is attached to a primary system, motion of the absorber body in more than one degree of freedom (DOF) relative to the primary system can be used to attenuate vibration of the primary system. In this paper, we propose that more than one mode of vibration of an absorber body relative to a primary system be tuned to suppress single-mode vibration of a primary system. We cast the problem of optimization of the multi-degree-of-freedom connection between the absorber body and primary structure as a decentralized control problem and develop optimization algorithms based on the H2 and H-infinity norms to minimize the response to random and harmonic excitations, respectively. We find that a two-DOF absorber can attain better performance than the optimal SDOF absorber, even for the case where the rotary inertia of the absorber tends to zero. With properly chosen connection locations, the two-DOF absorber achieves better vibration suppression than two separate absorbers of optimized mass distribution. A two-DOF absorber with a negative damper in one of its two connections to the primary system yields significantly better performance than absorbers with only positive dampers.


2021 ◽  
pp. 107754632110264
Author(s):  
Grigorios M Chatziathanasiou ◽  
Nikolaos A Chrysochoidis ◽  
Dimitris A Saravanos

Tuned mass dampers are well-known devices for efficient reduction of structural vibrations; however, they can only control the vibration of a single mode in a narrow frequency range and are not easily retunable. This article presents a semi-active tuned mass damper, consisting of a piezoelectric device connected to an external resistive–inductive electric circuit, which enables multi-modal vibration control, is highly tunable, and introduces high damping. The dynamics of the coupled electromechanical system, which includes the primary and auxiliary masses, the piezoelectric device, and the shunt circuit, are analyzed and the effect of the resistance and inductance is investigated. An experimental prototype using a specialty piezoelectric device is fabricated and tested. The experimental measurements greatly agree with the analytical results, validating the strong electromechanical coupling and the enhanced vibration suppression capabilities of the proposed damper. Moreover, the variation of inductive impedance demonstrates substantial semi-active broadband multi-modal vibration control potential, by introducing an additional highly tunable electromechanical resonant oscillator in the system dynamics, and also by enabling the enhancement of coupling and energy dissipation on targeted modal frequencies.


2021 ◽  
Vol 83 (6) ◽  
pp. 125-139
Author(s):  
Afham Zulhusmi Ahmad ◽  
Aminudin Abu ◽  
Lee Kee Quen ◽  
Nor’azizi Othman ◽  
Faridah Che In

This paper presents a systematic experimental investigation on the performance of a Multiple Tuned Mass Dampers (MTMDs) attached to a structural system under dynamic load excitation. A Modal Experimental Analysis (EMA) of a three-story structural frame equipped with a viscous damper system was carried out through a series of shaking table tests to evaluate the performance and verify the analysis approach. Each of the TMDs consists of a mass attached to a structural floor via Thermoplastic Polyurethane (TPU) viscous bearing. Initially, the TMD was designed solely to control single mode vibration and then the mechanism is extended for the application of controlling multimode responses. The experiment demonstrated that the proposed viscous dampers exhibit good performance in reducing the response of structures under dynamic loads, and able to control both fundamental and higher vibration modes of a Multiple Degree of Freedom (MDOF) primary system effectively. It was also evident that the attachment of the air dashpot dampers to each of TMDs lead to better efficiency on controlling the amplification of the damper mass and significantly contribute to better structural modal tuning.


2021 ◽  
pp. 107754632098430
Author(s):  
Fan Yang ◽  
Ramin Sedaghati ◽  
Ebrahim Esmailzadeh

To date, considerable attention has been paid to the development of structural vibration suppression techniques. Among all vibration suppression devices and techniques, the tuned mass damper is one of the most promising technologies due to its mechanical simplicity, cost-effectiveness, and reliable operation. In this article, a critical review of the structural vibration suppression using tuned mass damper technology will be presented mainly focused on the following four categories: (1) tuned mass damper technology and its modifications, (2) tuned mass damper technology in discrete and continuous structures (mathematical modeling), (3) optimization procedure to obtain the optimally designed tuned mass damper system, and (4) active tuned mass damper and semi-active tuned mass damper with the practical realization of the tuned mass damper technologies.


2013 ◽  
Vol 35 (3) ◽  
Author(s):  
Nguyen Van Khang ◽  
Trieu Quoc Loc ◽  
Nguyen Anh Tuan

There are problems in mechanical, structural and aerospace engineering that can be formulated as Nonlinear Programming. In this paper, the problem of parameters optimization of tuned mass damper for three-degree-of-freedom vibration systems is investigated using sequential quadratic programming method. The objective is to minimize the extreme vibration amplitude of vibration models. It is shown that the constrained formulation, that includes lower and upper bounds on the updating parameters in the form of inequality constraints, is important for obtaining a correct updated model.


Author(s):  
Semen Kopylov ◽  
Zhaobo Chen ◽  
Mohamed AA Abdelkareem

Implementation of tuned mass dampers is the commonly used approach to avoid excessive vibrations in civil engineering. However, due to the absence of the compact dimension, there are still no practical applications of the tuned mass dampers in automotive industry. Meanwhile, recent investigations showed the benefit of utilizing a tuned mass damper in a vehicle suspension in terms of driving comfort and road holding. Thus, the current investigation aimed to explore a novel compact dimension tuned mass damper, which can provide both sufficient vibration mitigation and energy harvesting. This paper presents a prototype of a back-iron-based design of an electromagnetic regenerative tuned mass damper. The mathematical model of the tuned mass damper system was developed and has been validated by the experimental results of the tuned mass damper prototype implemented in a protected mass test-bench. The indicated results concluded that the attenuation performance dramatically deteriorated under random excitations and a reduction in the root-mean-square acceleration of 18% is concluded compared to the case with undamped tuned mass damper. Under harmonic excitations, the designed tuned mass damper prototype is able to reduce the peak acceleration value of the protected structure by 79%. According to the experimental results, the designed tuned mass damper prototype revealed a peak regenerative power of 0.76 W under a harmonic excitation of 8.1 Hz frequency [Formula: see text]m amplitude. Given the simulated random road profiles from C to E, the back-iron electromagnetic tuned mass damper indicated that root-mean-square harvested power from 0.6 to 6.4 W, respectively.


2019 ◽  
Vol 22 (11) ◽  
pp. 2449-2463
Author(s):  
Jun Chen ◽  
Ziping Han ◽  
Ruotian Xu

Dozens of human-induced load models for individual walking and jumping have been proposed in the past decades by researchers and are recommended in various design guidelines. These models differ from each other in terms of function orders, coefficients, and phase angles. When designing structures subjected to human-induced loads, in many cases, a load model is subjectively selected by the design engineer. The effects of different models on prediction of structural responses and efficiency of vibration control devices such as a tuned mass damper, however, are not clear. This article investigates the influence of human-induced load models on performance of tuned mass damper in reducing floor vibrations. Extensive numerical simulations were conducted on a single-degree-of-freedom system with one tuned mass damper, whose dynamic responses to six walking and four jumping load models were calculated and compared. The results show a maximum three times difference in the acceleration responses among all load models. Acceleration response spectra of the single-degree-of-freedom system with and without a tuned mass damper were also computed and the response reduction coefficients were determined accordingly. Comparison shows that the reduction coefficient curves have nearly the same tendency for different load models and a tuned mass damper with 5% mass ratio is able to achieve 50%–75% response reduction when the structure’s natural frequency is in multiples of the walking or jumping frequency. All the results indicate that a proper load model is crucial for structural response calculation and consequently the design of tuned mass damper device.


2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Abdollah Javidialesaadi ◽  
Nicholas E. Wierschem

In this study, a novel passive vibration control device, the three-element vibration absorber–inerter (TEVAI) is proposed. Inerter-based vibration absorbers, which utilize a mass that rotates due to relative translational motion, have recently been developed to take advantage of the potential high inertial mass (inertance) of a relatively small mass in rotation. In this work, a novel configuration of an inerter-based absorber is proposed, and its effectiveness at suppressing the vibration of a single-degree-of-freedom system is investigated. The proposed device is a development of two current passive devices: the tuned-mass-damper–inerter (TMDI), which is an inerter-base tuned mass damper (TMD), and the three-element dynamic vibration absorber (TEVA). Closed-form optimization solutions for this device connected to a single-degree-of-freedom primary structure and loaded with random base excitation are developed and presented. Furthermore, the effectiveness of this novel device, in comparison to the traditional TMD, TEVA, and TMDI, is also investigated. The results of this study demonstrate that the TEVAI possesses superior performance in the reduction of the maximum and root-mean-square (RMS) response of the underlying structure in comparison to the TMD, TEVA, and TMDI.


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