Traditional Tuned Mass Dampers Research Articles

Active vibration control for flexible towers based on displacement observation and reduced-order controller in modal space: Theory and experiment

Active vibration control is not only suitable but also urgently needed in order to mitigate excessive vibration for dynamic systems such as wind turbine towers. However, there is a challenge of directly observing displacement and developing an efficient reduced-order control strategy. With this in view, a reduced-order controller based on displacement observation is developed for the vibration mitigation of flexible high towers, where the problems of low signal-to-noise ratio (SNR) and intricate acceleration-based control algorithms are eliminated completely. The displacement can be measured by laser or modern videometrics technology. A reduced-order model with an active mass damper (AMD) at the top of the tower is created using modal truncation approach based on modal participation factor (MPF), which successfully preserves the dominant modes of the original structure, and reduces the influence of high-frequency uncertainties. Considering structure uncertainties caused by environmental factors and aging process, an unscented Kalman filter (UKF) is introduced to identify the modal stiffness of the reduced-order model. The present study, using a 5 MW onshore wind turbine as an example, investigates active vibration control under wind and seismic loads and compares it with traditional tuned mass damper (TMD). From a dynamic perspective, the simplified model of wind turbine tower takes the form of a multi-degree-of-freedom series model. Consequently, a six-story steel frame platform has been constructed to experimentally validate the efficacy of the reduced-order controller. According to numerical simulation and laboratory testing, the control effect of the reduced-order controller with a few displacement states as feedback can be utilized as an active control strategy for high-rise flexible towers.

Seismic performance of soft soil foundation with a new type of assembled wall tuned mass damper.

The design of tuned mass damper (TMD) parameters is influenced by the soil-structure-TMD coupling system; thus, it is important to consider the soil-structure interaction (SSI) for the vibration control effect of the TMD. Recently, the acquisition of TMD parameters considering soil-structure interactions has only remained at the theoretical stage, lacking relevant experimental verification. Traditional TMD face the problems of occupying a large building space, increasing construction costs, and non-replaceable components. In this study, an assembled wall-type damping TMD was designed. By comparing the dynamic response of the uncontrolled and controlled structures equipped with the newly assembled wall-type damping TMD in the shaking table test on a soft soil foundation, we analyzed whether the SSI effect was considered in the TMD design parameters on the damping effect of the newly assembled wall-type tuned mass damper. The TMD parameters optimized using the artificial intelligence algorithm were verified experimentally. The results indicated that the traditional TMD design parameters were discordant because the SSI effect was not considered. The SSI effect in the soil effectively reduces the dynamic response of the superstructure. By considering the SSI effect and improving the multi-population genetic algorithm, a wall-type damping TMD with optimized parameters can achieve a good damping effect.

Vibration control and stroke evaluation of bi-directional bistable nonlinear energy sinks applied in monopile offshore wind turbines during emergency shutdown

Monopile offshore wind turbines (OWTs) in complex wind and wave environments can generate more excessive vibrations in the fore-aft (FA) and side-to-side (SS) directions when emergency shutdowns occur, and therefore damping techniques to alleviate such vibrations are essential. Due to the potential frequency detuning (reduced damping effectiveness) of traditional tuned mass dampers (TMDs) and stroke issues (such as large strokes of TMDs and limited maximum strokes of unidirectional nonlinear energy sinks (NESs)) in existing absorbers, this paper proposes a bi-directional bistable nonlinear energy sink (BBNES) to mitigate the vibration of the OWT in the FA and SS directions during the emergency shutdown. First, the proposed device and its operation mechanism are elaborated, and an optimization method for the device is introduced. Then, the dynamic analysis model of the BBNES is developed for vibration control of the OWT and incorporated into a fully coupled numerical simulation tool with high fidelity, FAST v8. Subsequently, the responses of the OWT without and with the proposed BBNES and the bi-directional tuned mass damper (BTMD) are exhaustively investigated under diverse conditions (including mass ratios, wind-wave loadings, emergency shutdown times, wind-wave misalignments, and 1st mode natural frequencies of the OWT) to reveal their performances and compare them. The research results show that under most conditions, the BBNES and BTMD have a similar damping performance in the FA direction, whereas the BBNES has a slightly lower damping performance in the SS direction than the BTMD. In addition, except for the wind velocity of 8 m/s at the hub and the wind-wave misalignment of 90°, the FA stroke of the BBNES with a small mass ratio (i.e., 0.01∼0.035) is significantly smaller than that of the BTMD with the same mass ratio by more than 1.1 m, and even up to about 4 m. The SS stroke of the BBNES is slightly greater than that of the BTMD, and in most cases, the difference between both is less than 0.52 m. Therefore, the BBNES is superior to the BTMD in this regard. When the 1st mode natural frequency of the OWT decreases, the BTMD can lose its tuning efficacy and makes the tower more susceptible to resonance caused by 1p and wave loadings, while the BBNES is not affected by the 1st mode natural frequency variation of the OWT, demonstrating its stronger robustness.

Design and Performance Assessment of Base Isolated Structures Supplemented with Vibration Control Systems

This paper investigates the implementation of supplemental vibration control systems (VCS) in base isolated (BI) structures, to improve their dynamic performance. More specifically, the aim of the VCS is to reduce the base displacement demand of BI structures, and at the same time mitigate the superstructure seismic responses. The purpose of the examined VCS is dual, and for this reason a multi-objective optimization methodology is formulated for the design of the VCS. The examined vibration absorbers include modifications of the KDamper concept. The KDamper is an extension of the traditional Tuned Mass Damper (TMD), and introduces a negative stiffness (NS) element to the additional oscillating mass of the TMD. The generated NS force is exactly in phase with the inertia force of the added mass, thus, artificially amplifying it. This way, lighter configurations are possible with an enhanced damping behavior. These VCS are designed based on engineering criteria and manufacturing constraints, while the excitation input used in the multi-objective optimization procedure is selected from a dataset of artificial accelerograms, designed to be spectrum-compatible with the EC8 design acceleration response spectrum. The effectiveness of the examined VCS is also assess with real near-fault earthquake records, and a comparison is performed with TMD-based VCS having 50 times larger additional masses. The numerical results demonstrate the superiority of the KDamper-based VCS in improving the dynamic behavior of BI structures over other mass-related systems (TMD).

Analytical optimization and performance evaluation of non-traditional tuned mass damper for stochastic base excited structures considering dual solutions

Compared with traditional tuned mass damper (TMD), non-traditional tuned mass damper (NTMD) has higher damping efficiency in some conditions. Nevertheless, the analytical optimization problem of NTMD has not been well solved; especially, multiple optimal solutions are not discussed. In this study, the closed-form optimal expressions of the NTMD using tuning stiffness are derived based on H 2 norm optimization. And the vibration mitigation performance of the NTMD is evaluated considering dual-solutions situation subjected to typical ground motion and impulse excitation. Different from solving the unique optimal frequency ratio, there exist two sets of optimal stiffness and damping ratio derived using tuned spring elements for given mass ratio, and the effective mass ratio is also limited as 1/3. The vibration mitigation or isolation performance and robustness of H 2 optimized NTMD with higher stiffness ratio are far superior to NTMD with lower stiffness ratio. NTMD using larger optimal tuning stiffness ratio also can be seen as an optimized form of Maxwell model using additional mass. Hence, using a large stiffness, namely, a large frequency ratio to design NTMD is recommended, which is different from traditional TMD. The case of NTMD with large stiffness can be adopted when the demands of practical engineering are not met using the optimal parameters of small stiffness. And a compromise scheme can also be provided, which are the combination with a larger mass ratio but is less than the maximum limit value 1/3 and a not very large stiffness ratio but is exceeded 0.5 according to demands of practical engineering.

A tuned cable-inerter system for wind turbine blades vibration suppression

With low damping in the edge-wise of the wind turbine blade, significant damage can be caused by the high-amplitude vibrations resulting from environmental loads. This paper proposes the use of a tuned cable-inerter system (TCIS) to mitigate the edge-wise vibration of the blades by exploiting the bending deformation of the blade. Firstly, the TCIS is studied analytically, and a reduce-order blade-TCIS model is established for describing the dynamic behavior. A closed-form solution allowing for parameter optimization is then derived based on the fixed-point theory. Subsequently, a coupling wind turbine model with the TCIS is established. By employing the NREL 5MW wind turbine as a benchmark model, the feasibility of the TCIS is verified in both frequency and time domain. The simulation results show that the TCIS performs superior in reducing the blade response with smaller stroke, compared with the traditional tuned mass damper (TMD) and tuned mass damper with inerter (TMDI). The investigation on feasibility of TCIS in blade vibration control shows potential value for utilization in the narrow spaces of wind turbine blades without additional weight on the blade. Furthermore, the closed-form solution offers an analytical method for rapid and effective parameters optimization.

Vibration control of offshore wind turbines with a novel energy-adaptive self-powered active mass damper

Slender and flexible offshore wind turbines (OWTs) are vulnerable to external dynamic excitations, and passive tuned mass dampers (TMDs) have been widely used to control excessive vibrations of OWTs under harsh marine environments (e.g., strong winds and irregular sea waves). However, TMDs are only effective in the vicinity of the controlled frequency, i.e., in a narrow frequency band. Compared to passive TMDs, active control methods are normally considered to possess better control performances but at the cost of a large amount of external energy input. To this end, the present study proposes a novel energy-adaptive self-powered active mass damper (SPAMD) to mitigate the responses of OWT towers. The proposed control device can harvest energies from OWTs and then use them as the power to drive an active mass damper for structural vibration control. Specifically, a representative OWT is selected as a prototype structure and its tower is modeled as a multi-degree-of-freedom system by simplifying the rotor-nacelle assembly as a lumped mass and moment of inertia. The dynamic characteristics (mainly natural frequency and mode shape) of the tower obtained by the developed model are validated against a finite element model. Subsequently, the system configuration and working mechanism of SPAMD are introduced and SPAMD is incorporated into the developed model to simultaneously harvest energy and mitigate the fore-aft responses of the tower under wind and sea wave loads. The control effectiveness of SPAMD is further compared to the traditional TMD. Results show that SPAMD has a superior effect over TMD in controlling OWT responses.

Performance Evaluation of Inerter-Based Dynamic Vibration Absorbers for Wind-Induced Vibration Control of a Desulfurization Tower

High-rise flue gas desulfurization towers are susceptible to wind loads, which can cause instability and failure in the along-wind and across-wind directions. The tuned mass damper (TMD) has been widely applied in the wind-induced vibration control of high-rise structures. To enhance the control performance and reduce the auxiliary mass of TMD, this study focuses on inerter-based dynamic vibration absorbers (IDVAs) for controlling the vibration response of a desulfurization tower. The dynamical equations of the tower–IDVA systems are established under wind loads, and a parameter optimization strategy for IDVAs is proposed by using the genetic algorithm. The performance of the traditional TMD and six IDVAs in the vibration control of the tower are systematically compared. Numerical simulations demonstrate that both the TMD and IDVAs can substantially mitigate the vibration response of the tower. However, compared to the TMD with the same response mitigation ratio, more than 34% of the auxiliary mass can be reduced by two optimal IDVAs. In addition, the energy dissipation enhancement and lightweight effect of the two IDVAs are explained through parametric studies.

Field testing and performance evaluation of AMD-controlled high-rise building structures with real-world validation

In recent decades, structural control of civil infrastructures, especially high-rise buildings, has been broadly investigated and developed to mitigate disaster-induced structural responses. The traditional tuned mass damper (TMD) has been exploited to the active mass damper (AMD) system, which leads to the necessary field testing and performance evaluation. Accordingly, a comprehensive dynamic testing and performance evaluation method is proposed in this paper for high-rise structures with AMD systems. Four testing scenarios are firstly adopted and investigated at the field testing stage, including ambient vibration, free vibration, forced vibration, and dynamic loading vibration. Correspondingly, a multi-level performance evaluation framework, sequentially containing direct response data analysis, modal characteristic identification, AMD excitation performance validation, and vibration control efficiency evaluation, is designed and presented for the control performance evaluation and confirmation. To illustrate the presented multi-scenario dynamic testing and multi-level performance evaluation framework, a field dynamic testing was systematically conducted on a real-world tall tower with an AMD system. In the first testing part, the tower's critical dynamic characteristics, such as natural frequency, damping ratio, and modal mass, are accurately identified. Subsequently, the control performance of the AMD system is evaluated by analysis of the excitation and actuation capacity and the structural vibration control efficiency. Furthermore, the amplitude dependency of the damping ratio is identified, and the potential mechanism is discussed.

Closed-form solutions for the optimal design of lever-arm tuned mass damper inerter (LTMDI)

Tuned mass damper inerter (TMDI) has become a popular choice for vibration control in flexible structures, including long-span bridges, due to its superior performance compared to traditional tuned mass dampers (TMDs), such as improved control effect and smaller static displacement. However, the control effect of TMDI is heavily reliant on the spanning distance of inerter, which typically generates a significant internal additional moment due to the force imbalance, limiting the practical application of TMDI on flexible structures. For this reason, a novel lever-arm TMDI (LTMDI) is proposed in this study, to suppress the vibrations of long-span bridges. The non-dimensional governing equations of the bridge-LTMDI system are established in modal coordinates, and the closed-form solutions of the optimum frequency and damping ratios of LTMDI are derived based on the classical fixed-point theory. Parametric studies are conducted to investigate the influences of the fulcrum position, modal shape ratio, mass ratio, inertance ratio and asymmetric mode on the control effectiveness. Moreover, for comparison, the control effectiveness of LTMDI is further compared to those of the TMD and TMDI. Finally, a long-span bridge is selected as an example to demonstrate the effectiveness of LTMDI in reducing vortex-induced vibration (VIV). The results show that the LTMDI has superior control effect and space feasibility as compared to the TMD and TMDI in both frequency and time domains. The derived analytical formulas can accurately determine the optimal parameters, providing a simple yet efficient guideline for the application of LTMDI in flexible structures.

Combined Tuned Mass Dampers for structural vibration control

A Combined Tuned Mass Damper (CTMD), including a Tuned Liquid Column Damper (TLCD) integrated on the top of a traditional Tuned Mass Damper (TMD), is proposed to control vibrations of a Single Degree-Of-Freedom (SDOF) structure. This device can also be considered as a new hybrid type of tuned mass damper. The gained results from the parametric study indicate that the mass ratio between the TLCD and the TMD significantly affects the CTMD's effectiveness. In order to assess the structural vibration absorption capacity of this device, the effectiveness and robustness of an optimized CTMD are compared with those of optimum TMD and TLCD with the same weight as the CTMD. The numerical simulations show that the proposed CTMD provides a higher performance over a broader excitation frequency domain compared with both a conventional TMD and TLCD in mitigating structural vibration. Furthermore, the frequency response curve of the structure using the CTMD is relatively flat, whereas the frequency response curves of the structure with the TMD and TLCD remain a two-peak characteristic on the same frequency range considered. In another aspect, although the optimum CTMD is not more robust than the TMD or TLCD in resisting the change of the structural stiffness, it offers a wider range for choosing the frequency and damping ratio to aim at remaining similar efficiency to that of the optimized TMD (or TLCD). Therefore, a CTMD is much more robust than a single TMD or TLCD having equal weight to the CTMD. For parameters of the CTMD, the present research also indicates that the damping ratio of the TMD does not display an essential role in the CTMD. In contrast, although the TLCD mass is much smaller than the TMD mass, the appearance of the TLCD is very important in this device.

Vibration control of steel frames with setback irregularities equipped with semi-active tuned mass dampers

This paper presents a pioneering study on the seismic vibration control of steel moment-resisting frames (MRFs) with setback irregularities using semi-active tuned mass dampers (SATMDs). The research investigates the efficiency and the location of the SATMDs and compares their efficiency with traditional tuned mass dampers (TMDs) for the vibration control of setback structures with different vertical irregularities. To assess the nonlinear seismic performance of buildings with setbacks, various engineering demand parameters such as inter-story drift ratio, story displacement, story velocity, story acceleration, and base shear factor were analyzed under earthquake excitations. The results reveal that the use of SATMDs reduced the seismic response of irregular frames with setbacks. In addition, the efficiency of SATMDs in the control of setback frames was more than the regular frames. Also, the investigations showed that placement of the control systems at the roof level of the structure significantly reduced the structural vibration of irregular structures. It is noticeable that the use of these control devices requires more attention for structures with significant setbacks because, in some cases, the response of a structure with SATMDs can be greater than an uncontrolled structure.

Seismic performance investigation of building structures equipped with MTMDs considering soil-structure interaction

The traditional tuned mass damper (TMD) design criterion is obtained with the fixed base model, which is suitable for the case without significant soil-structure interaction (SSI) effects. However, when the SSI effects are notable, the TMD designed based on the fixed base model will degrade its performance and even magnify the seismic response of the main structure. Since accurately evaluating the effects of SSI on the natural frequencies of the main structure is difficult due to soil nonlinearity, single tuned mass dampers (STMDs) may easily undergo tuning failure due to frequency-limited control bandwidths. Applying multiple tuned mass dampers (MTMDs) to attenuate the vibration of the main structure may be a promising solution. In this paper, the seismic performance of a 10-story steel structure equipped with MTMDs considering SSI is investigated. A three-dimensional refined finite element model is first built. Then, a comprehensive analysis is presented by considering the different MTMDs design parameters and earthquakes. The research results show that when the SSI effect is significant, the MTMDs in reducing the seismic response of the structure have better effectiveness than the STMDs. With other MTMDs design parameters determined, the MTMDs performance is strengthened by increasing the mass ratio and the number of TMDs. The central frequency ratio is taken as the optimum frequency ratio. The bandwidth is limited to the region formed by 0.9–1.1 times the TMD optimal design frequency. The performance of the MTMDs is less influenced by the different TMD installation positions. Moreover, the MTMDs still have good robustness when considering the SSI effect.

Multiple hazards vibration control of jacket offshore wind turbines equipped with amplifying damping transfer systems: Winds, waves, and earthquakes

This paper investigated the vibration control problem of jacket offshore wind turbines (JOWTs) caused by multi-hazards including winds, waves, and earthquakes through amplifying damping transfer system (ADTS), which transfers the rotation of upper turbine tower to the jacket platform, making it convenient to install viscous dampers to dissipate external energy. Moreover, ADTS significantly amplifies the rotation deformation to fully drive the viscous damper. Different from traditional tuned mass damper (TMD) which may lose its effectiveness for higher modes, ADTS provides additional damping to both fundamental and higher modes of JOWT, resulting in better performance in resisting multiple hazards. For example, the displacements of turbine tower in JOWTs subjected to winds, waves, and earthquakes are mitigated by about 23.05%, 63.41%, and 48.96%, respectively; in the meantime, the turbine accelerations subjected to those hazards are also reduced by about 34.28%, 62.72%, and 35.27%. Moreover, ADTS also provides considerably response reduction effect to the supporting jacket of JOWTs.

Performance Evaluation of Inerter-Based Dampers for Bridge Flutter Control: A Comparative Study

As the number of long-span bridges continues to grow, wind-induced vibration issues have become increasingly intensified. Among them, flutter is a serious wind-induced vibration that can lead to bridge collapse. To address this problem, this paper proposes inerter-based dampers as a solution for flutter control and compares their performance to traditional tuned mass dampers (TMDs). Firstly, eight distinct inerter-based dampers were proposed, based on various combinations of mass-inerter-spring-damper (MISD) components. Secondly, the equations of motion of the bridge-MISD system were derived based on the two-mode coupled flutter theory and the mechanical impedance analysis method. Thirdly, the flutter control performance of the eight proposed MISDs is examined using a simply supported beam, with the six better-performing dampers further evaluated using the Jiangyin Bridge. The results show that inerter-based dampers can effectively improve the critical flutter wind speed of bridges, with performance sensitive to frequency. Additionally, incorporating an inerter decreases the static displacement of the mass block, while increasing the mass of MISD and the distance between the damper and the section center improves flutter control performance. The optimal spring stiffness ratios for the six MISDs are identified, largely dependent on the damper’s inertance and mass. In conclusion, this paper offers a promising solution to addressing flutter in long-span bridges and provides insights into the design and optimization of inerter-based dampers.

The optimal design of negative stiffness inerter passive dampers for structures

The combination of negative stiffness devices and inerters to traditional base isolators (TBI) and tuned mass dampers (TMD) does not exist in any state-of-the-art. Therefore, to pursue the research using the above-mentioned research scope, the negative stiffness inerter passive dampers such as negative stiffness inerter-based base isolators (NSIBI), negative stiffness base isolators (NSBI), negative stiffness inerter-based tuned mass dampers (NSITMD), and negative stiffness tuned mass dampers (NSTMD) are introduced in this paper. H2 and H∞ optimization methods are applied to derive the exact closed-form expressions for the optimal design parameters of these novel passive vibration dampers. Newton’s second law applies to derive the governing equations of motion of the controlled structures. The transfer function formation and Newmark-beta method are applied to determine the dynamic responses of the controlled structures analytically and numerically. Hence, H2 optimized NSIBI and NSBI have 45.98% and 46.71% more dynamic response reduction capacities than optimum TBI. In addition, H∞ optimized NSIBI and NSBI have 58.36% and 57.32% more dynamic response reduction capacities than optimum TBI. Furthermore, the optimum NSITMD and NSTMD have 0.42%, 10.84%, and 4.5%, 13.48% more dynamic response reduction capacities than traditional TMD. All the derivations are mathematically accurate.

A Hybrid Damper with Tunable Particle Impact Damping and Coulomb Friction

A particle impact damper (PID) dissipates the vibration energy of a structure through impacts within the damper. The PID is not commonly used in practice mainly because of its low damping-to-mass ratio and the difficulty in achieving its optimal design due to its nonlinear characteristics. In contrast, a Coulomb friction damper (FD) can offer a higher damping force-to-mass ratio than other dampers, but it is also difficult to be controlled precisely due to its nonlinear characteristics and excessive frequency sensitivity regarding the resonant frequency. This paper examines a hybrid damper by combining a particle impact damper and a Coulomb friction damper (PID + FD) theoretically and experimentally. A theoretical model of the proposed damper is developed and tested numerically on a single-degree-of-freedom (SDOF) structure. The predicted results are validated by experimental tests on a prototype of the proposed damper. The damping force provided by the FD in the prototype can be varied by adjusting the normal force applied through a compression spring, while the vibration energy dissipation by the PID can be varied by changing the cavity size of the PID. A parametric analysis of the proposed hybrid damper has been performed. The proposed hybrid damper can reduce the maximum vibration amplitude of the SDOF primary structure by 66% and 43% compared with using the FD and PID only. The proposed damper is found to be effective over a wide range of excitation frequencies. Furthermore, the proposed hybrid damper achieves a similar vibration suppression performance to the traditional tuned mass damper (TMD) of a similar mass ratio. The proposed damper does not require an optimally tuned natural frequency and damping, unlike the TMD, and therefore it does not have the detuning problem associated with the TMD. In addition, the performance of the proposed damper is tested and compared with the TMD for random earthquake excitation data. Consequently, the proposed hybrid damper may be a simpler and better alternative to the TMD in passive vibration control applications.

Performance evaluation of a nonlinear energy sink with quasi-zero stiffness property for vertical vibration control

The advantages of nonlinear energy sink (NES) have been proven to effectively reduce vibrations in the horizontal direction. The application of NES devices to suppress vertical vibration is still at an early stage. In this study, a new type of NES that works in the vertical direction, where disc springs and viscous dampers are utilized to connect an additional mass with the primary structure, is proposed. The NES device can provide a cubic restoring force characterized by the quasi-zero stiffness (QZS) property. Initially, the equations of motion of the primary structure supplemented with NES were established. Then, the force and displacement transmissibility curves were obtained via the steady-state analysis for the NES-controlled, tuned mass damper (TMD)-controlled, and uncontrolled systems. Analytical results revealed that the targeted energy transfer (TET) property of the NES can absorb the kinetic energy within the operating range without amplifying the response in the lower and higher frequency ranges. In contrast, TMD is more efficient within the operating range. Finally, a practical large-span floor structure was adopted to compare the operating performance of NES and TMD. External vibration includes track-induced vibration, vertical earthquake, and human-induced vibration. Numerical results show that the NES performs better than traditional TMD in controlling the vertical response. Moreover, the addition of a NES device will not potentially amplify the response on some occasions.

Seismic-induced vibration control of a multi-story building with double tuned mass dampers considering soil-structure interaction

This paper presents a methodology for the optimization of double tuned mass dampers (TMDs) positioned on the top floor of a multi-story building subjected to ground motions considering soil-structure interaction (SSI). In the optimization process, it is considered that double TMDs are connected both in series and in parallel. STMD and PTMD are used to denote the series TMDs and parallel TMDs, respectively. The equations of motion for an n-story shear building controlled by STMD and PTMD are derived by considering the SSI effect and the optimum parameters of both devices are obtained by minimizing the amplitude of the displacement transfer function for the top floor of the building in the frequency domain analysis. The effectiveness of the PTMD and STMD designed using the Jaya algorithm (JA) is verified by numerical examples of a ten-story shear building under twelve earthquake records with different frequency content and the comparison with the traditional TMD is also performed. In order to investigate the effect of earthquake frequency content on the control performance of the TMDs, earthquakes considered are divided into three different groups as low, intermediate, and high-frequency contents. In addition, the influence of the soil stiffness on the optimum parameters and effectiveness of the PTMD and STMD is discussed. Numerical results show that the optimally designed PTMD and STMD effectively suppressed the maximum floor displacements and accelerations of the building. It is also shown that SSI effects can be ignored when the building is built on stiff soil. In addition, it is concluded that the SSI and earthquake frequency content have a significant effect on the control performance of TMDs and the seismic response of the building.

Robust optimum design of tuned mass dampers for high-rise buildings subject to wind-induced vibration

<p style='text-indent:20px;'>Control devices are commonly applied to suppress structural displacement due to dynamic loads. In this work, a study of the optimum tuned mass dampers (TMDs) design was carried out, installed in a high-rise building subject to wind-induced vibration. Tuned mass dampers are the most known passive energy device and their design are an important area of study. A mathematical model to consider the wind force in the time domain was introduced. A procedure to obtain the robust design of tuned mass dampers was proposed through the optimization under uncertainties, which considers the uncertainties present in the structural properties of the building and also in the dynamic excitation. This method led to the robust design of TMDs, whereas the device performance became insensitive to the randomness of the input variables of the optimization problem. The robust design was compared with a design obtained by a deterministic optimization and the advantages of using an optimization under uncertainties are shown. In addition, the proposed methodology was compared with traditional TMD design methods, showing again the superiority of the proposed methodology.</p>