Tuned Mass Damper Research Articles

Optimization of multiple rotational inertia double tuned mass damper for offshore wind turbines under earthquake, wind, and wave loads

This study introduces a framework for designing an optimal multiple rotational inertia double tuned mass damper (MRIDTMD) with multiple tuning frequencies to effectively mitigate vibrations in offshore wind turbines (OWTs) subjected to combined wind, wave, and seismic loads. The framework comprises a coupled numerical model of an OWT with an MRIDTMD, an intelligent optimization algorithm, and parallel computing technology. First, coupled governing equations of motion for an OWT with an MRIDTMD under seismic conditions are derived based on multibody dynamics and fully coupled analysis theories in FAST v8. Subsequently, an MRIDTMD submodule is developed and integrated into FAST v8 to establish a coupled analysis model for an OWT with MRIDTMDs using an updated simulation tool. Furthermore, an intelligent optimization algorithm and parallel computing technology are introduced to establish the framework, and the MRIDTMDs are optimized. Moreover, the efficiency of the optimized MRIDTMD is assessed based on observed reductions in the OWT responses under combined seismic cases. Subsequently, comparisons with an optimized multiple tuned mass damper (MTMD) and a parametric study are conducted. The effectiveness and robustness of the optimized MRIDTMD and the improved mitigation effects of the MRIDTMD compared with the MTMD owing to the additional inerter are proved.

Optimization Study of a Tuned Mass Damper for a Large Monopile Wind Turbine

Passively tuned mass dampers (TMDs) are known to effectively mitigate the vibration of wind turbines. However, existing literature predominantly examines their application in damping vibrations of the tower or platform, overlooking the potential benefits of installing TMDs on the turbine blades themselves. This study investigates the impact of wind and wave loads on TMD damping effectiveness and proposes a comprehensive damping strategy involving TMDs installed in both the nacelle and the blades. The design optimized the mass and stiffness of these TMDs to enhance their performance. Results indicate that, as wind speeds increased from 12 m/s to 24 m/s, the power spectral density at the tower’s natural frequency (0.22 Hz) more than doubled. Notably, TMDs exhibited robust vibration damping capabilities under high wind speeds. Specifically, at wind speeds of 24 m/s, TMDs reduced anterior–posterior and lateral displacement at the tower top by 61.2% and 166.8%, respectively, when two TMDs were combined. Conversely, the study found that TMDs did not significantly improve vibration damping at lower to moderate wind speeds. This research underscores the importance of optimizing TMDs for high wind conditions to ensure wind turbine stability and mitigate potential vibration-related risks effectively under varying environmental loads, including wind and waves. It offers valuable insights for the refined design and deployment of TMDs in wind energy applications.

Evaluate the Dynamic response of Buildings to Seismic Forces, Considering the Interaction between human Occupants and Structural vibrations

Damage to buildings and other structures may occur when dynamic loads, caused by earthquake vibrations, drive the ground and everything related to it to shake in a complicated way. Civil engineers are always thinking of new methods to deal with this inevitable problem. Humans put stress on a variety of buildings, including floors, footbridges, stadiums, and more. Modern material and manufacturing technology, together with human desire for aesthetics, have made it possible to build long span structures like bridges, stadiums, floors, etc. that are sleek, lightweight, and slim. To dampen a structure's dynamic reaction, engineers use devices called (TMDs), which consist of a mass and a spring, are tuned mass dampers. When it comes to managing the structural reactions to wind and harmonic excitations, Tuned Mass Damper (TMD) is the way to go. Specifically, the shear beam and 1D lumped-mass beams are the models under consideration. The main purpose of this piece is to demonstrate how methods that use records of ambient vibration may enhance and supplement seismic risk assessments of preexisting structures. To compare the structure's reaction with and without TMD, or tuned mass damper, is mounted on the building's exterior. Using a model calculated from outside vibrations and recorded within the structure, we were able to effectively compare the building's motion to a fake ground motion. It was also determined the inter-storey drift and the stiffness of each floor.

Effect of PGV/PGA ratio on seismic-induced vibrations of structures equipped with parallel tuned mass dampers considering SSI

Tuned mass damper is one of the effective methods used to reduce dynamic loads in structures under the influence of environmental loads such as earthquakes, wind, and traffic loads. In the current TMD design, the fixed base approach is mostly considered when determining the dynamic properties of the structure. However, in cases where the structure-soil interaction (SSI) is important, the frequency values of the structure are significantly different from those obtained for the fixed foundation approach. This situation negatively affects the performance of TMD operating in a narrow frequency range. Therefore, using a control system consisting of multiple TMDs connected in parallel (MTMD) instead of a single TMD may be a promising solution for the control of structural vibrations. In this study, a parameter design and efficiency assessment of MTMD for reducing the seismic responses of the structure considering SSI is studied. The particle swarm optimization (PSO) algorithm is adopted to obtain the optimum parameters (i.e., damping ratio, frequency ratio, and frequency bandwidth) of the MTMD. The effects of different support conditions, number of TMD units, and peak ground velocity (PGV) / peak ground acceleration (PGA) ratio on the performance of MTMD are also evaluated comprehensively. The dynamic responses of the structure are obtained under 42 near -fault ground motions from the time history analysis. The results reveal that ground motions with low PGV/PGA ratio can significantly increase the responses of the structure for both with and without SSI cases. Moreover, it has been observed that optimized TMDs placed parallel to the top floor of the structure are effective in reducing the seismic responses of a ten-story building considering SSI.

Seismic performance investigation of PCS water tank designed as tuned mass damper (TMD) for nuclear containment plant considering soil-structure interaction

Tuned mass damper (TMD) has been applied in civil engineering fields to reduce the seismic response. However, few TMDs are used in the nuclear structure due to the huge additional mass of the traditional TMD device on the nuclear structure. In this paper, the PCS water tank of a nuclear structure is reconstructed into a TMD system to reduce the seismic response of the nuclear structure. The proposed novel water tank-TMD device can use its characteristics of large mass to achieve the tuned shock absorption effectively while maintaining the original function of the water tank. Moreover, more and more nuclear power structures are being built on non-bedrock sites, and the effects of soil-structure interaction (SSI) on the seismic response and seismic migration performance of nuclear power structures need to be reasonably considered. The effects of SSI and auxiliary plants on the seismic response of the nuclear containment plants equipped with PCS water tanks are first investigated. Subsequently, the performance of the water tank-TMD system in reducing the seismic responses of nuclear containment plants is analyzed in detail by considering the effect of SSI, design frequency of TMD, and design criteria of TMD. The research results show that the proposed water tank-TMD system can effectively reduce the seismic response of nuclear containment plants. Besides, it is necessary to consider the influence of SSI on the dynamic characteristics of the structure in the design of TMD when the SSI effect is strong. The water tank-TMD system designed according to the TMD criteria proposed by Sadek et al., and Salvi and Rizzi has better reduction performance compared with that designed by other design criteria.

Tuned mass dampers ‐ evaluation of the effect on two real footbridges

AbstractPedestrian comfort, subtle design, minimizing the number of fixed supports of the footbridge or material saving. These are the key arguments for integrating tuned mass dampers into the bridge project. The goal is to protect people and structure from vibrations and damage. The following paper presents findings from the design, production and tuning of mass dampers, their optimization possibilities and benefits for bridge engineering. The validity of damper design was verified on two footbridges in the Czech Republic and Slovakia. It concerns the footbridge over the Svitava River in Bílovice nad Svitavou and the footbridge over the high‐speed road in Banská Bystrica. Dynamic tests including measurement were carried out on both bridges before and after the installation of the dampers. The dynamic monitoring of the compliance of modal parameters was conducted using operational modal analysis (OMA). The evaluation of the dynamic tests also includes the response to pedestrian effects (comfort criteria) and the determination of the logarithmic decrement of the damping.

Band gap generation in cantilever beams through periodic material removal

Traditional methods for generating band gaps in beams usually involve adding periodic elements like tuned mass dampers or masses, or applying complex geometrical changes. This research suggests a subtraction-based method achieved by removing material in the thickness direction through straightforward machining operations, thus forming periodic cells. The numerical studies start with band gap analysis, using periodic theory to assess different periodic cell configurations. This is followed by numerical and experimental studies on cantilever beams, each containing a set number of these periodic cells. Non-contact vibration measurements are conducted on one plain and six machined aluminum beams using a multipoint laser vibrometer and an automated impact hammer. The experimental findings corroborate the band gaps predicted by the numerical model, confirming the effectiveness of this approach. The study notes that the optimal periodicity of the cells and the contrast in thickness vary with the beam’s dimensions, and that the thickness contrast markedly affects the quantity, width, and intensity of the resulting band gaps. These results indicate that (1) periodic material removal in beam-like structures allows improved vibration reduction while mass is reduced, and (2) manufacturing can play a key role in vibration control in simple structures.

Experiments on sloshing mitigation using tuned oscillating baffles

We experimentally confirm the efficacy of submerged oscillating baffles for sloshing mitigation in a partially filled open container of water. As with the more typical applications of tuned mass dampers, when the natural frequency of the baffle is close to that of the first sloshing mode, the main resonance peak is split into two peaks of lower amplitude. The reduction in resonant sloshing amplitude is superior to that of a fixed baffle.

Cable‐stayed footbridge in Lover Vítkovice Area‐DOV

AbstractA cable‐stayed footbridge for pedestrians and cyclists is situated in post‐industrial landscape Lover Vitkovice Area (DOV) of Ostrava. The bridge has two independent sections, 84,3 m and 68,3 m long that leads across the Ostravice river and the railway corridor directly towards the recent blast furnace. The bearing structure consists of outer lattice trusses and the lower steel orthotropic deck and is characterised by outstanding variable shape created by architect. The bridge's deck is supported by three and two pairs of cables, which run directly from top of the middle stiff pylon. Cables are connected to bottom chords of the structure by cylindrical fork with threaded rod and the tie rod structural system with rolled thread (turnbuckles, forks with pin and conical lock covers). The paper describes manufacturing, erection and pre‐stressing procedure, dynamic properties and design and installation of tuned mass dampers.

Performance of differently arranged double-tuned mass dampers for structural seismic response control including soil-structure interaction

Reducing vibrations occurring in structures under environmental loads makes a significant contribution to the development of structural safety. Tuned mass dampers (TMD) are one of the systems commonly used to control structural vibrations. Since TMD is adjusted according to the dominant frequency of the structure, factors that may cause changes in the frequency of the structure can significantly reduce the effectiveness of TMD. One of the main factors that can cause changes in the frequency values of the structure is the interaction between the structure and the soil. To overcome this situation, it is recommended to apply control systems consisting of multiple TMDs (MTMD) to the main structure instead of a single TMD. MTMD systems are arranged in two different types, serial and parallel. In this paper, a methodology that considers the structure-soil interaction (SSI) is presented for the optimum design of control systems with different configurations placed on a main structure under the influence of ground motion. To research the SSI effects, the TMDs-structure coupled system is supported by rocking and swaying springs and the corresponding dashpots, and then the equations of motions of the structural system are derived. In the optimization process based on particle swarm optimization in the frequency domain, different soil types, configuration types, and mass ratios are considered. The efficiency of optimum TMDs arranged in series and parallel is also evaluated using near and far fault ground motions in the time domain. Numerical results show that if structures are constructed on soils with low shear wave velocities, ignoring SSI can significantly change the design parameters and effectiveness of the control system.

Effectiveness of vibro-impact nonlinear energy sinks for vibration suppression of beams under traveling loads

Effective control of traveling-load-induced vibrations is a challenging issue of special significance in various engineering fields such as railways, bridges, cable systems, etc. Traditional passive strategies that rely on tuned mass dampers are effective over only a narrow traveling velocity range, thus cannot meet the broadband requirement for such problems. In this paper, a nonlinear device termed as vibro-impact nonlinear energy sink (VINES), that including a light-weight mass moving in-between the clearance of the primary structure, is proposed as a mean for the broadband control of vibrations induced by traveling loads. To do this, we considered a coupled system consisting of a beam as a host structure under traveling loads, and coupled to a set of VINESs. The system is modeled in a dimensionless formula in order to gain generalized results, and the vibro-impact dynamics is solved from a measure differential complementarity problem that is given by Signorini’s contact law. Comprehensive analyses are then conducted to investigate the vibration reduction potential of the VINES regarding the underlying nonlinear mechanisms, parametric effects, as well as robustness concerns. It is found that effective vibration reduction could be achieved by adding a simple VINES with a total mass around 10% of the host beam. Moreover, such a simple strategy shows an excellent broadband property to suppress multiple peaks, as well as a desirable robustness to perform well under excitation uncertainty and different traveling conditions.

Exploring the Structural Response of High-Rise Buildings using Fuzzy Logic and Genetic Algorithms

Exploring the dynamic behaviour of high-rise buildings presented a critical challenge. In this study, Fuzzy Logic and Genetic Algorithm (FLGA) were employed to comprehensively investigate the structural response of high-rise buildings (HRBs) for adaptive vibration control systems employing semiactive damper devices. The study integrated a fuzzy logic inference system with a Genetic Algorithm (GA) to create FLGA, which was then employed in a 3-story shear building under real earthquake conditions and multi-dimensional wind loads. The analytical model for a semi-active tuned mass damper (STMD) was examined and evaluated before integrating it into the proposed FLGA system. The results indicated that FLGA reduced story acceleration by an average of 20% and story drift by approximately 50% while efficiently controlling the structure within allowable movement limits and resident comfort criteria under multi-directional wind loads. The suggested optimal controller mitigated both displacement and acceleration responses by 15 to 20% without amplification. The study demonstrated FLGA's effectiveness as a model-free control strategy for managing structural response uncertainties.

Particle Tuned Mass Dampers for Wind-Induced Vibration Control in Supertall Building Tower Crowns

This study aims to investigate the performance of Particle Tuned Mass Damper (PTMD) in mitigating wind-induced vibrations in tower crown structures, providing findings to tower crowns with hinged boundary conditions in supertall buildings. A multi-degree-of-freedom (MDOF) model of the tower crown and a PTMD model based on the discrete element method (DEM) are established and validated. The intermediate story is a suitable choice for arranging damping devices in hinged tower crown structures. By analyzing the vibration response of the tower crown structure with PTMD under wind excitation, the study reveals the vibration mitigation effects of PTMD and the particle energy dissipation mechanism. The results indicate that the vibration reduction ratios of peak displacement and acceleration for the tower crown are 12.29% and 14.53%, respectively. Field test experiment shows its effectiveness from another perspective. Additionally, the energy dissipation between particles is the primary method of energy dissipation during collisions, accounting for approximately 80% of the total dissipated energy. Furthermore, the wide tuning frequency band characteristic of PTMD is examined through experimental testing, and its damping performance is compared with traditional Tuned Mass Damper (TMD) and Multiple Tuned Mass Damper (MTMD). Finally, the research findings, limitations, and potential impacts are discussed. This study contributes to advancing the development of tower crowns and their vibration reduction technology.

Investigating criteria for the optimisation of single and multiple tuned mass dampers

Investigating criteria for the optimisation of single and multiple tuned mass dampers

Optimization of tuned mass dampers – minimization of potential energy of elastic deformation

A tuned mass damper (TMD) optimization can be performed under various assumptions and objectives. All the variables of the optimization, such as structural model, performance index and load type affect the optimal parameters of the TMD. This paper presents a new optimization method that implements straightforward performance index and allows taking load spectral characteristics into account. Thanks to the usage of modal coordinates, the method allows fast numerical optimization of TMD attached to large or complicated structures with numerous degrees of freedom. One of the complicated tasks while optimizing TMD is the choice of a performance index. In this paper, the mean value of potential energy stored in the elastic deformation of a structure under periodic load serves as a performance index, which leads to a low numerical complexity task if the optimization is performed in the frequency domain. The new method also allows a simple inclusion of load spectral characteristics and permits TMD optimization for any loading spectral range. When applied to a structure with a single degree of freedom, this method leads to H2 optimization in the case of white noise excitation. However, it is applicable to multiple degrees of freedom structures with single or multiple TMDs and any given load. The paper also presents several examples of numerical optimization of the TMD attached to both single and multiple degrees of freedom structures under various loads, including white noise excitation, pedestrian load, and earthquake strong motion.

Investigation on vibration control of TetraSpar floating offshore wind turbine

The stability of offshore wind turbines during operation is crucial, and as an emerging technology, the TetraSpar floating offshore wind turbine demonstrates commendable stability. Moreover, it can effectively reduce the levelized cost of energy (LCOE) in production and installation. However, There is relatively scarce research on its dynamic response and reliability under complex ocean conditions. To reduce the vibration response of floating offshore wind turbines in complex marine environments and improve the stability of the turbines, it is necessary to establish a fully coupled dynamic model to study the multi-field coupled dynamic response and vibration control of the turbines. In light of this, this paper establishes a multi-physical field coupled dynamic model for TetraSpar floating offshore wind turbine through an F2A coupling framework, integrating aerodynamics, servo-elasticity, hydrodynamics, and mooring dynamics. The study analyzes the vibration suppression effects of different Tuned Mass Dampers (TMDs) on the wind turbine system. Using the two main response frequencies, 0.0367Hz and 0.57Hz, in the front and rear directions of the wind turbine as the tuning frequencies for TMD. The best vibration reduction effect was achieved by comparing multiple sets of TMD with different parameters. Analysis shows that TMD can significantly reduce the standard deviation of bending moment and tension of steel bars before and after tower foundation, with maximum values of 38.76% and 73.02%, respectively. At the same time, TMDs also impose a burden on wind turbines, such as a maximum increase of 2.23% in the average values of tower base bending moment, platform pitch, and tower top longitudinal displacement, which also slightly increase under extreme sea conditions. However, compared to the significant vibration suppression effect of TMD, it can be ignored.

Research on semi-active vibration reduction of offshore wind turbine structure combined eddy current theory with tuned mass dampers

At present, the offshore wind power gradually shows a development trend towards the profound ocean with characteristic of larger capacity, higher tower and longer blades. Therefore, the offshore wind turbine (OWT) is more vulnerable to extreme loads and may lead to the negative influence of structural vibration safety. In this research, a new semi-active eddy current tuned mass damper (SEC-TMD) was proposed for the vibration control of OWT structures and its vibration reduction effect under multiple kinds of dynamic loads was also discussed. Firstly, taking one actual 3.0 MW OWT supported by bucket foundation as object, the SEC-TMD was designed based on the linear quadratic optimal control (LQR) algorithm and bounded Hrovat optimal control algorithm in order to obtain the optimal control force of structural vibration systems. The relationship between damping coefficient and magnetic conductivity spacing was further fitted to achieve variable damping control of SEC-TMD. Secondly, the theoretical model of 3.0 MW OWT structure installed with SEC-TMD was established and the effectiveness of the established theoretical model was verified through the comparison on modal analysis between the theoretical calculations and measured data identification. Finally, the vibration reduction effect of SEC-TMD on the measured OWT structure under wind-wave, seismic and vibration amplification conditions was analyzed and compared with the results calculated from the other passive dampers including EC-TMD and TLCD. It is shown that the maximum reduction percentage of peak value for vibration displacement and acceleration on the tower top can respectively reach 31.93 %, 44.11 %, 30.20 % and 54.57 %, 33.94 %, 31.75 % under three above conditions. Comparing with EC-TMD and TLCD, the better vibration reduction effect indicates that the proposed SEC-TMD has good engineering application value for the vibration suppression of OWT.

A novel casing-pipe type TMD for seismic control of free-spanning submarine pipelines: Shaking table tests and numerical simulations

Submarine pipelines are vital lifeline engineering structures for transporting offshore oil and gas resources, which may experience adverse vibrations against structural safe operation when encountering strong offshore earthquakes. This paper proposes an innovative casing-pipe type tuned mass damper (CPTMD) for the seismic control of free-spanning submarine pipelines (FSSPs). The design concept and control mechanism of the CPTMD are firstly presented. Both shaking table tests and numerical simulations are performed to examine the effectiveness of using the CPTMD to reduce seismic-induced vibration of FSSPs, through comparing structural seismic responses with and without damper device. In the experimental and numerical studies, the effect of seawater around submarine pipelines is simplified using the added hydrodynamic mass method. The experimental and numerical results consistently demonstrate that the proposed CPTMD has a good capacity for suppressing seismic-induced vibration of FSSPs. Moreover, the impacts of stiffness, damping coefficient, mass ratio and casing-pipe length on the seismic control effectiveness of the CPTMD device are investigated and discussed comprehensively, and the optimal values of these design parameters are determined. As a result, the proposed CPTMD could be an effective and simple solution for the vibration control of FSSPs induced by offshore seismic motions.

Dynamic performance of a supertall building with an active tuned mass damper system during Super Typhoon Saola

This paper investigates the dynamic characteristics (natural frequencies and damping ratios) of a 600-m-tall supertall building with an active tuned mass damper (ATMD) system during Super Typhoon Saola. Based on the wind speed, wind direction, and wind-induced acceleration response records by the structural health monitoring (SHM) system installed on the skyscraper, the wind characteristics during the passage of Saola are first investigated, and the relations between the mean wind speeds atop the skyscraper and the root-mean-square (RMS) acceleration responses are established. Then, employing the stochastic subspace identification (SSI) method and an uncertainty quantification method, this paper comprehensively investigates the uncertainty bounds, time-varying features, and amplitude-dependency characteristics of the modal parameters with and without the operation of the ATMD system. Next, on the basis of the identified modal parameters and time-frequency analysis, the performance and effectiveness of the ATMD system in suppressing the wind-induced vibrations of the skyscraper is investigated. Lastly, the structural health condition is evaluated from the perspective of building natural frequency and damping ratio changes before and after the typhoon hit. The goal of this study is to advance the understanding of the wind effects on supertall buildings and provide useful information for the wind-resistant design and vibration control of supertall buildings in tropical cyclone-prone regions.

Design of a novel intelligent adaptive fractional-order proportional-integral-derivative controller for mitigation of seismic vibrations of a building equipped with an active tuned mass damper

The primary objective of this study is to introduce a novel adaptive fractional order proportional–integral–derivative (FOPID) controller. The adaptive FOPID controller’s parameters are dynamically adjusted in real-time using five distinct multilayer perceptron neural networks. The extended Kalman filter (EKF) is employed to facilitate the parameter-tuning process. A multilayer perceptron neural network, trained using the error Backpropagation algorithm, is employed to identify the structural system and estimate the plant. The real-time estimated Jacobian is applied to the controller to control the model. The stability and robustness of the adaptive interval type-2 fuzzy neural networks controller are enhanced by utilizing the EKF and the feedback error learning strategy for compensator tuning. This improvement increases resilience against estimation errors, seismic disturbances, and unknown nonlinear functions. The primary objective is to address the challenges posed by maximum displacement, acceleration, and drift, as well as the uncertainties arising from variations in stiffness and mass. In order to validate the reliability of the proposed controller, the performance investigation is carried out on an 11-story building equipped with an active tuned mass damper under far and near-field earthquakes. Numerical findings show the remarkable effectiveness of the proposed controllers compared to their predecessors. In addition, it is revealed that the inclusion of the adaptive interval type-2 fuzzy neural networks compensator has increased the performance of the proposed controller and shows significant capabilities in reducing the seismic responses of structures during severe earthquake events.