Tuned Mass Dampers

Engineering Structures, 1998

This paper summarizes the results of a parametric study performed to enhance the understanding of some important characteristics of tuned mass dampers (TMD). The effect of detuning on some of the TMD parameters on the performance is studied using steady-state harmonic excitation analysis and time-history analysis. The El Centro and Mexico excitations are used for time-history analysis. The effects of tuning criteria and significance of numerical tuning are also studied. The correspondence between the design of a TMD for a SDOF structure and a certain mode of a MDOF structure is drawn to simplify TMD design to control a single mode of a multimodal structure. An example is given to illustrate the design procedure. Investigations are made regarding controlling multiple structural modes using multi-tuned mass dampers (MTMD).

Earthquake Engineering & Structural Dynamics, 1995

Damper (TMD) analogy, equivalent mass, stiffness and damping of the TLD are calibrated from the experimental results. These parameters are functions of the TLD base amplitude. Some important properties of the TLD are discussed on the basis of these results.

Journal of Advances and Scholarly Researches in Allied Education

Now a days, structures are continuously increasing in the construction industries which are having a very low damping value. The structures can easily fail under structural vibrations induced by earthquake and wind, some several techniques are available today to control the vibration of the structure, TMD is one of these techniques are use today. Some investigations are carried out to identify the importance and performance of tuned mass damper in different structures. In this thesis, a one-storey and a two-storey building frame models are developed for shake table experiment under sinusoidal excitation to observe the response of the structure with and without TMD. The TMD is tuned to the structural frequency of the structure keeping the stiffness and damping constant. Various parameters such as frequency ratio, mass ratio, tuning ratio etc. are considered to observe the effectiveness and robustness of the TMD in terms of percentage reduction in amplitude of the structure. Then the responses obtained are validated numerically using finite element method. From the study it is observed that, TMD can be effectively used for vibration control of structures.

HAL (Le Centre pour la Communication Scientifique Directe), 2015

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Vibration, 2018

Tuned Mass Dampers (TMDs) are widely used for the control and mitigation of vibrations in engineering structures, including buildings, towers, bridges and wind turbines. The traditional representation of a TMD is a point mass connected to the structure by a spring and a dashpot. However, many TMDs differ from this model by having multiple mass components with motions of different magnitudes and directions. We say that such TMDs have added mass. Added mass is rarely introduced intentionally, but often arises as a by-product of the TMD suspension system or the damping mechanism. Examples include tuned pendulum dampers, tuned liquid dampers and other composite mechanical systems. In this paper, we show how a TMD with added mass can be analyzed using traditional methods for simple TMDs by introducing equivalent simple TMD parameters, including the effective TMD mass, the mass of the equivalent simple TMD. The presence of added mass always reduces the effective TMD mass. This effect is e...

International Journal of Scientific Research in Science and Technology, 2021

Dampers are significant part of structure in the highlight increment seismic opposition. As they increment the life of structure, toughness and flexiblity. In various power condition the conduct of damper assumes a significant job, which shows the need of damper .So it is important to concentrate to make its utilization in better manner.

The response of tall buildings subjected to dynamic wind loads has been widely studied. For excitations approaching the resonant frequencies of the structure, ensuring serviceability is a significant concern. One traditional solution is the implementation of a tuned mass damper (TMD), which acts as a passive damping device in the region of the tuned frequency. However, TMDs exhibit a limited bandwidth and often require a significant mass. Active systems, such as the active mass driver, have been utilized to improve the effectiveness of the TMD concept, but these systems require significant power and bring the inherent risk of instability. Hybrid semi-active schemes with variable damping devices have been proposed. They are stable, require low power, and are controllable, thus providing a broader range of applicability. The concept of a semi-active tuned mass damper (STMD) has been investigated, but the influence of the dynamic range of the semi-active damping device has not been documented. This analysis assesses the effectiveness of STMD systems using a variable-orifice damper and a magnetorheological damper with varying dynamic ranges. Results demonstrate a performance dependence on the dynamic range and also elucidate the superiority of non-linear damping devices. It is shown that the prescribed TMD mass may be reduced by a factor of two when semi-active control is implemented, thereby making the STMD an attractive and feasible option when space and weight concerns govern design.

Archive of Applied Mechanics, 2019

The tuned mass damper (TMD) is a widely used passive control device which is attached to a main system to suppress undesired vibration. In this paper, a non-traditional form of TMD system is investigated. Unlike the traditional TMD configuration, the considered TMD system has a linear viscous damper connecting the absorber mass directly to the ground instead of the main mass. There have been some studies on the optimization design of the non-traditional TMD (NT-TMD) for undamped main structures. Those studies have indicated that the NT-TMD provides better performance than the traditional TMD does. When there is a frequency shifting in the structural frequency or tuning frequency of TMD, to the best knowledge of the authors, there has been no study on the performance of the NT-TMD. The main idea of the study is to investigate the effect of frequency detuning on the control performance of the NT-TMD. The optimum parameters of the NT-TMD system and corresponding effectiveness are obtained for different mass ratios of the NT-TMD system. The numerical results indicate that the NT-TMD with high mass ratio provides better robustness to the changes in the target frequency ratio than the traditional TMD.

Journal of Civil and Environmental Engineering, 2021

Modern structures such as floor systems, pedestrian bridges and high-rise buildings have become lighter in mass and more flexible with negligible damping and thus prone to vibration. In this paper, a semi-actively controlled pendulum tuned mass dampers (PTMD) is presented that uses air springs as both the restoring (resilient) and energy dissipating (damping) elements; the tuned mass damper (TMD) uses no passive dampers. The proposed PTMD can readily be fine-tuned and re-tuned, via software, without changing any hardware. Almost all existing semi-active systems have the three elements that passive TMDs have, i.e., inertia, resilient, and dissipative elements with some adjustability built into one or two of these elements. The proposed semi-active air suspended TMD, on the other hand, is made up of only inertia and resilience elements. A notable feature of this TMD is the absence of a physical damping element in its make-up. The required viscous damping is introduced into the TMD using a semi-active control scheme residing in a micro-controller which actuates a high-speed proportional valve regulating the flow of air in and out of the air springs. In addition to introducing damping into the TMD, the semi-active control scheme adjusts the stiffness of the TMD. The focus of this work has been the synthesis and analysis of the control algorithms and strategies to vary the tuning accuracy, introduce damping into air suspended PTMD, and enable the PTMD to self-tune itself. The accelerations of the main structure and PTMD as well as the pressure in the air springs are used as the feedback signals in control strategies. Numerical simulation and experimental evaluation of the proposed tuned damping system are presented in this paper.

Studies have already demonstrated the successful use of linear semiactive damping devices, such as variable orifice (VO) dampers, for semiactive TMD systems. More recently, nonlinear semiactive damping devices, such as magnetorheological (MR) dampers, have also been shown to be effective for semiactive control of TMDs. Though semiactive dampers differ widely, with responses ranging from linear (VO) to nonlinear (MR), criteria for choosing an optimal semiacive device for a TMD have not been rigorously developed. This paper expands knowledge of semiactive TMD systems by assessing the effect of nonlinearity in the damping device on the effectiveness of a semiactive TMD. This is achieved by simulating a variable damping device (linear), and a variable friction device (nonlinear). The variable damping device consists of a VO damper, while the variable friction device consists of a new mechanically robust and reliable damping device with a dynamic resembling the MR damper. These simulations allow the influence of nonlinearity to be investigated and provide further insight into selecting an optimal semiactive damping device for improving the performance of a passive TMD.