Amortiguadores de masa sintonizada: una revisión general

The loads generated by seismic events and strong winds are forces of nature that subject civil works to extreme situations, generally causing the failure of structures and in many cases, the loss of human lives. In order to face these forces of random character and difficult to predict, structural engineering proposes design and construction regulations that are mandatory in most countries of the world, which allow the structures to adequately resist the imposed forces. And as history has shown, sometimes a good design is not enough, so seismic-resistant engineering develops new methodologies and devices that help to further protect structures when they are subjected to actions such as earthquakes and winds. In order to face these challenges, mechanisms such as shock absorbers and controllers appear, grouped as passive, active, semi-active and hybrid devices, with innovative designs that greatly contribute to give greater safety and confidence to our civil works. This article presents a general overview of seismic dampers and controllers, their historical development, mechanical and analytical models, scopes, strengths and weaknessesLas cargas que generan los eventos sísmicos y los fuertes vientos son fuerzas de la naturaleza que someten a las obras civiles a situaciones extremas, lo que provoca eventualmente la falla de las estructuras y en muchas ocasiones, la pérdida de vidas humanas. Para enfrentar estas fuerzas de carácter aleatorio y de difícil predicción, la ingeniería estructural plantea normativas de diseño y construcción de obligatorio cumplimiento en la mayoría de los países del mundo, que permiten que las estructuras puedan resistir de manera adecuada las fuerzas impuestas. Y como la historia lo ha demostrado, algunas veces un buen diseño no es suficiente, por lo que la ingeniería sismoresistente desarrolla nuevas metodologías y dispositivos que ayuden a proteger aún más a las estructuras cuando se ven sometidas a acciones como los sismos y los vientos. Para afrontar estos retos, aparecen mecanismos como los amortiguadores y controladores, agrupados como dispositivos pasivos, activos, semiactivos e híbridos, con diseños innovadores que contribuyen en gran medida a dar mayor seguridad y confianza a nuestras obras civiles. En este artículo se presenta una visión general de los amortiguadores de masa sintonizada, su desarrollo histórico, modelos mecánicos y analíticos, alcances, fortalezas y debilidades. The loads generated by seismic events and strong winds are forces of nature that subject civil works to extreme situations, generally causing the failure of structures and in many cases, the loss of human lives. In order to face these forces of random character and difficult to predict, structural engineering proposes design and construction regulations that are mandatory in most countries of the world, which allow the structures to adequately resist the imposed forces. And as history has shown, sometimes a good design is not enough, so seismic-resistant engineering develops new methodologies and devices that help to further protect structures when they are subjected to actions such as earthquakes and winds. In order to face these challenges, mechanisms such as shock absorbers and controllers appear, grouped as passive, active, semi-active and hybrid devices, with innovative designs that greatly contribute to give greater safety and confidence to our civil works. This article presents a general overview of seismic dampers and controllers, their historical development, mechanical and analytical models, scopes, strengths and weaknesses

The tuned mass-damper-inerter for harmonic vibrations suppression, attached mass reduction, and energy harvesting

In this paper the tuned mass-damper-inerter (TMDI) is considered for passive vibration control and energy harvesting in harmonically excited structures. The TMDI couples the classical tuned mass-damper (TMD) with a grounded inerter: a two-terminal linear device resisting the relative acceleration of its terminals by a constant of proportionality termed inertance. In this manner, the TMD is endowed with additional inertia, beyond the one offered by the attached mass, without any substantial increase to the overall weight. Closed-form analytical expressions for optimal TMDI parameters, stiffness and damping, given attached mass and inertance are derived by application of Den Hartog’s tuning approach to suppress the response amplitude of force and base-acceleration excited single-degree-of-freedom structures. It is analytically shown that the TMDI is more effective from a same mass/weight TMD to suppress vibrations close to the natural frequency of the uncontrolled structure, while it is more robust to detuning effects. Moreover, it is shown that the mass amplification effect of the inerter achieves significant weight reduction for a target/predefined level of vibration suppression in a performance-based oriented design approach compared to the classical TMD. Lastly, the potential of using the TMDI for energy harvesting is explored by substituting the dissipative damper with an electromagnetic motor and assuming that the inertance can vary through the use of a flywheel-based inerter device. It is analytically shown that by reducing the inertance, treated as a mass/inertia-related design parameter not considered in conventional TMD-based energy harvesters, the available power for electric generation increases for fixed attached mass/weight, electromechanical damping, and stiffness properties

Passive, semi-active, active and hybrid mass dampers: A literature review with associated applications on building-like structures

In this paper, a state-of-the-art literature review is presented emphasising on the development of control variants for mass damper schemes on building-like structures. Additionally, a systematic literature review is conducted addressing three relevant questions: What type of mass damper is preferable by the associated industry? How are mass dampers distributed around the world? Is industry following research? Through the systematic literature review, updated lists of mass damper implementations and control algorithm applications in real-life structures were compiled. 208 case-studies are discussed in total. It is found that, 63% of them refer to passive tuned mass dampers, 31% to hybrid mass dampers, 4.0% to active mass dampers and only 2% to semi-active mass dampers. Regarding control algorithms, controllers of 24 structures driving semi-active, active or hybrid mass dampers are presented. It is concluded that the industry considerably lags behind latest structural control research both regarding implementations and overall management

Self-tuning vibration absorber and the effect of its installation position on damping characteristics

A kind of self-tuning vibration absorber is presented. The relationship between the installation position and the vibration damping effect of the self-tuning vibration absorber is established, the influence on the damping effect is discussed. Then, on the vibration test bed, the theoretical analysis results are tested and verified. The results show that, installation position of the self-tuning vibration absorber has a significant influence on its vibration damping effect. When installed near the source location, the self-tuning vibration absorber has a better vibration damping effect. It is should be avoided in the area of vibration deterioration

Hybrid Passive Control Strategies for Reducing the Displacements at the Base of Seismic Isolated Structures

In this paper, the use of hybrid passive control strategies to mitigate the seismic response of a base-isolated structure is examined. The control performance of three different types of devices used for reducing base displacements of isolated buildings is investigated. Specifically, the Tuned Mass Damper (TMD), the New Tuned Mass Damper (New TMD) and the Tuned Liquid Column Damper (TLCD), each one associated to a Base Isolated structure (BI), have been considered. The seismic induced vibration control of base-isolated structures equipped with the TMD, New TMD or the TLCD is examined and compared with that of the base-isolated system without devices, using real recorded seismic signals as external input. Data show that the New TMD is the most effective in controlling the response of base-isolated structures so that it can be considered as a practical and appealing means to mitigate the dynamic response of base-isolated structures

Principle Study of a Semi-active Inerter Featuring Magnetorheological Effect

Inerters are two-terminal mass elements in which the forces applied at the terminals are proportional to relative acceleration between the nodes. The volume and weight of inerters are much smaller than those of any conventional mass element for the same force, which is beneficial for engineering applications. The inerter in mechanical systems corresponds completely to the capacitor in electrical systems, which makes it more convenient to do related investigations based on mechanical-electrical analogies. A semi-active inerter (SAI) featuring a magnetorheological (MR) effect with tunable inertance is proposed, designed, and investigated to enhance the performance of the passive inerters. The proposed SAI consists of a flywheel, a flywheel housing, a ball screw, a connection sleeve, bearings, upper and lower covers, excitation coils, and MR fluid. MR fluid fulfilled in the flywheel housing of the SAI is energized by the excitation coils with applied current, and correspondingly the mechanical characteristics of the SAI are tunable via the applied current. The mathematical model and the mechanical performance of the SAI are established and tested, respectively. The nonlinearity of the experimental results is analyzed and the non-linear model of the SAI is further established. The preliminary principle verification of the continuous adjustment of the equivalent inertance of the SAI is conducted using the non-linear model. Moreover, a compensator is proposed to address the problem of the phase difference between the controllable force and the real output force of the SAI, and continuous inertance adjustment of the SAI with a compensator is realized

Invited Review: Recent developments in vibration control of building and bridge structures

This paper presents a state-of-the-art review of recent articles published on active, passive, semi-active and hybrid vibration control systems for structures under dynamic loadings primarily since 2013. Active control systems include active mass dampers, active tuned mass dampers, distributed mass dampers, and active tendon control. Passive systems include tuned mass dampers (TMD), particle TMD, tuned liquid particle damper, tuned liquid column damper (TLCD), eddy-current TMD, tuned mass generator, tuned-inerter dampers, magnetic negative stiffness device, resetting passive stiffness damper, re-entering shape memory alloy damper, viscous wall dampers, viscoelastic dampers, and friction dampers. Semi-active systems include tuned liquid damper with floating roof, resettable variable stiffness TMD, variable friction dampers, semi-active TMD, magnetorheological dampers, leverage-type stiffness controllable mass damper, semi-active friction tendon. Hybrid systems include shape memory alloys-liquid column damper, shape memory alloy-based damper, and TMD-high damping rubber

A review of the mechanical inerter: historical context, physical realisations and nonlinear applications

In this paper, a review of the nonlinear aspects of the mechanical inerter will be presented. The historical context goes back to the development of isolators and absorbers in the first half of the twentieth century. Both mechanical and fluid-based nonlinear inerter devices were developed in the mid- and late twentieth century. However, interest in the inerter really accelerated in the early 2000s following the work of Smith [87], who coined the term ‘inerter’ in the context of a force–current analogy between electrical and mechanical networks. Following the historical context, both fluid and mechanical inerter devices will be reviewed. Then, the application of nonlinear inerter-based isolators and absorbers is discussed. These include different types of nonlinear energy sinks, nonlinear inerter isolators and geometrically nonlinear inerter devices, many relying on concepts such as quasi-zero-stiffness springs. Finally, rocking structures with inerters attached are considered, before conclusions and some future directions for research are presented