Structural vibration is a common phenomenon existing in various engineering fields such as machinery, aerospace, and civil engineering. It should be noted that the effective suppression of structural ...vibration is conducive to enhancing machine performance, prolonging the service life of devices, and promoting the safety and comfort of structures. Conventional linear energy dissipative devices (linear dampers) are largely restricted for wider application owing to their low performance under certain conditions, such as the detuning effect of tuned mass dampers subjected to nonstationary excitations and the excessively large forces generated in linear viscous dampers at high velocities. Recently, nonlinear energy dissipative devices (nonlinear dampers) with broadband response and high robustness are being increasingly used in practical engineering. At the present stage, nonlinear dampers can be classified into three groups, namely nonlinear stiffness dampers, nonlinear-stiffness nonlinear-damping dampers, and nonlinear damping dampers. Corresponding to each nonlinear group, three types of nonlinear dampers that are widely utilized in practical engineering are reviewed in this paper: the nonlinear energy sink (NES), particle impact damper (PID), and nonlinear viscous damper (NVD), respectively. The basic concepts, research status, engineering applications, and design approaches of these three types of nonlinear dampers are summarized. A comparison between their advantages and disadvantages in practical engineering applications is also conducted, to provide a reference source for practical applications and new research.
•It is a highly interdisciplinary survey paper of the state-of-the-art technologies of nonlinear dissipative devices.•The typical nonlinear dissipative devices reported are nonlinear energy sink, particle impact damper and nonlinear viscous damper.•The broad scope of the paper will not only enhance the usefulness of this paper, but it will also attract wider readership to the Journal from various communities.
•The viscoelastic damping materials utilized in passive structural control devices for civil engineering applications are systematically classified and summarized.•A comprehensive review is presented ...including the testing protocols, the mechanical properties, the creeping, stress relaxation, and the fatigue in order to demonstrate the characteristics of tested viscoelastic materials.•Currently proposed analytical constitutive models of viscoelastic materials are systematically summarized and compared.
Structural control against earthquakes and other external dynamic loadings gains more importance given the burgeoning demand on the construction of various structures and high-rise buildings. Viscoelastic damper (VED) is a common type of passive control device to reduce structural vibrations. It is found that the performance of the VEDs is usually dominated by the vulcanized viscoelastic material (VEM) whose mechanical characteristics are sensitive to temperature, strain amplitude and excitation frequency. Due to the complex nature of the VEM compounds, the selection of such materials introduces degrees of uncertainty such that their performances in civil applications are rather scattered. Furthermore, existing efforts of various VEMs and the available analytical constitutive models were seldomly summarized despite the recent advancements of VEDs. This paper presents a critical review of the types, mechanical properties, testing protocols, and analytical models of VEMs considered for VED applications. In addition to the standard VEMs, the hybrid materials and the special VEMs are also summarized. Systematic comparisons of their efficiency, comparative advantages and disadvantages are presented. Besides, various analytical constitutive models to simulate the mechanical behavior of the VEMs are summarized. Finally, this paper identifies and highlights an ensemble of problems in the existing studies and the possible improvements that could be made in the future.
In order to reduce the displacement demand of the isolation layer under strong earthquakes, especially strong near fault pulse-like ground motions, the base isolation system-tuned mass damper inerter ...(BIS-TMDI) system is explored taking the nonlinear hysteretic characteristics of the isolation layer into inclusion. Likewise, different from traditional layout of the BIS-TMDI systems, the TMD is placed on the superstructure (such as first floor or third floor, etc.) rather than on the isolation layer and linked to the ground by an inerter. By resorting to the equivalent linearization method (ELM) and genetic algorithm (GA) optimization, the optimal design method of nonlinear BIS-TMDI system is established and then, the performance of the system is numerically investigated. Results demonstrate that the nonlinear BIS-TMDI system can significantly reduce the displacement demand of the isolation layer, and its control effectiveness and stroke performance are better than those of the nonlinear BIS-TMD system. The influences of the parameters of the superstructure, isolation layer, and earthquake ground motions on the vibration mitigation is further scrutinized. It follows that the robustness of nonlinear BIS-TMDI system is much better than that of nonlinear BIS-TMD system. Analyzing the nonlinear BIS-TMDI system subjected to the near-fault pulse-like ground motions, the superiority of the system in reducing the displacement of isolation layer, the responses of superstructure and the stroke performance of TMDI are further verified.
•An exploration is made on the nonlinear BIS-TMDI system different from its traditional layout.•Employing ELM and GA, the design method of nonlinear BIS-TMDI system is presented.•Reveal the parameter influence behaviors and conduct the time history analysis of nonlinear BIS-TMDI system.•The nonlinear BIS-TMDI system remarkably reduces the isolation layer displacement and has high overall performance.
The historical development and practical implementation of structural base isolation systems that work on the principle of friction are discussed in the light of analytical, numerical, and ...experimental studies carried out by researchers. Various parameters such as sliding velocity, surface temperature, axial pressure, vertical excitation along with near-field and far-field excitations that influence the overall performance of the isolation system have been explored. Merits and demerits of using traditional isolation systems and newly introduced smart and adaptive multiple surface isolators such as double concave and triple friction pendulum system is also discussed. Advantages and problems associated with friction base isolation systems are briefly explained with some future research suggestions, including practical experimental work and numerical simulations to verify the behavior of friction base isolation systems. Design optimization and optimal design utilizing some new and smart materials to achieve adaptive base isolation systems particularly incorporating complex problems, such as pressure, velocity, and temperature dependency along with multi-directional loadings.
•Friction based isolation systems enhance vibration control effectiveness and energy dissipation ability of the structure.•Adaptive behavior of multi sliding layers isolators makes isolation systems more robust.•Smart and adaptive isolation systems enhance structural damping under a variety range of seismic excitations.•Low cost nature and high efficiency of friction-based isolators are suitable for developing countries.
Earthquake-induced vibrations of wind turbines may compromise structural serviceability and safety. Most previous studies adopted passive control devices to mitigate the seismic responses of wind ...turbines. However, their control effectiveness is heavily dependent on the mass ratio between control devices and wind turbines, and they were typically housed at the tower top or within the nacelle. The restricted space within the hollow tower and the nacelle imposes considerable challenges for the implementation of such devices, rendering the application of large-scale control devices unfeasible for structural vibration control of wind turbines. To this end, this paper integrates a negative stiffness element within a conventional tuned mass damper (TMD), termed KDamper, to mitigate vibrations of wind turbine towers under seismic loads. Specifically, the widely used NREL 5 MW wind turbine is selected as a prototype structure and its tower is modelled as a multiple-degree-of-freedom system. Then KDamper is incorporated into the developed model and its parameters are optimized based on the H2 criterion. Subsequently, the control effectiveness of KDamper is investigated and compared with TMD in the frequency domain, and the control performances in terms of the effectiveness and robustness of KDamper are further examined under a series of earthquake records. Results show that KDamper has superior control effectiveness and robustness than TMD, indicating it has considerable potential for application in improving wind turbine performances against earthquake hazards.
•KDamper is proposed to control seismic responses of wind turbines.•KDampers with different negative stiffness and connecting configurations are optimized.•Control performances of KDampers are examined under a series of earthquake records.
Real-time hybrid simulation (RTHS) technique is an emerging method for investigating the structural dynamic behavior. This technique combines the advantages of numerical simulations with those of ...physical tests. Traditionally used in earthquake engineering, it is now gaining traction in wind and marine engineering. This study proposes a comprehensive RTHS methodology for monopile-support offshore wind turbines (OWTs, numerical substructure) equipped with vibration control devices (physical substructure). The proposed RTHS framework is characterized by its (i) multiscale substructures (i.e., full-scale numerical substructure and reduced-scale physical substructure), (ii) fluid–structure coupled numerical simulation (i.e., considering wind-blade and wave-monopile interactions) and (iii) multi-rate numerical calculation. The proposed approach is applied to a 5-MW monopile OWT equipped with a toroidal tuned liquid column damper. Verification tests are conducted to examine the feasibility and validity of the RTHS framework. The influences of wind-blade and wave-monopile interactions are revealed for different loading scenarios.
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•A real-time hybrid simulation methodology is proposed for OWTs with dampers.•The method allows full-scale simulation of OWTs and reduced-scale test of dampers.•FSI effects between air and blade, wave and monopile are considered in the method.•Distributed multi-rate computation technique is used to ensure the performance.•The quantitative impact of FSI effects on the test results is assessed.
Hybrid mass dampers (HMDs), which integrate tuned mass dampers with active mass dampers (AMDs) mounted on top, have been employed for vibration control in high-rise buildings. However, under varying ...loads, the stroke and control force of HMDs may exceed their design limits, potentially compromising the control effectiveness. The typically limited internal space within high-rise structures further highlights this issue. To address this issue, this study proposes a velocity-squared damping HMD (VSD-HMD) that combines a velocity-squared damping device (VSDD) with an AMD. A numerical model of the VSD-HMD-controlled Canton Tower is established, and the optimal relationship between the force and velocity of the VSDD is provided. Three different adverse wind-load scenarios are selected to assess the system performance using a linear quadratic Gaussian control strategy. Further verification is obtained through a real-time hybrid simulation (RTHS) of a scaled model of the Canton Tower. The results suggest that, in the VSD-HMD, the stroke and control force of the AMD as well as the stroke of the VSDD are lower than those in the HMD. The empirical data gathered from the RTHS are largely in agreement with the simulation results, proving the potential reliability and effectiveness of the proposed VSD-HMD and hybrid testing methodology.
•A hybrid mass damper with velocity-squared damping characteristics called VSD-HMD was proposed.•The numerical simulation analysis of VSD-HMD was carried out.•The effectiveness of the VSD-HMD was validated by real-time hybrid simulation.•The control performance of VSD-HMD is higher than that of HMD.
In this study, a new method that combines the tuned liquid column damper (TLCD) and the Savonius type hydrokinetic turbine (STHT) is proposed to harvest energy from mechanical vibrations of ...structures in a green power production way. The proposed approach converts hydrokinetic energy into electrical energy during the vibration control process. Excessive shaking table tests are performed to investigate the starting performance and energy conversion efficiency. An optimized circuit configuration is revealed for power maximization. The impact of STHT on the dynamic characteristics of TLCD is elaborated. In addition, a parallel circuit that allows both charging of energy storage components and vibration control is illustrated and experimentally verified. The results demonstrate the feasibility and characteristics of the approach in energy harvesting.
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•A new method is developed for energy harvesting from structural vibration.•A tuned liquid column damper is coupled with a Savonius type hydrokinetic turbine.•The impact on the dynamic behavior of the damper is elaborated.•The starting and energy conversion performances are experimentally studied.•A charging circuit that allows both energy storage and vibration control is shown.
Summary
By integrating the tuned tandem mass dampers (TTMD) with two inerters, the tuned tandem mass dampers‐inerters (TTMDI) with high effectiveness and wide frequency spacing (i.e., high ...robustness) have been proposed in this paper. It is expected that the frequency spacing of the TTMDI will be comparable with that of the multiple tuned mass dampers. In order to reveal the fundamental performance of the TTMDI, it is attached to a single degree of freedom (SDOF) structure under random Gaussian white noise base excitations. Closed‐form expressions for calculating the dimensionless displacement variances are thereupon derived for the SDOF structure–TTMDI system. The optimization criterion is determined as the minimization of the dimensionless displacement variances. Employing the gradient‐based optimization technique, the effects of varying the key parameters on the performance of the TTMDI are scrutinized in order to probe into its superiority. Evaluation of the performance of the TTMDI includes that of its effectiveness, strokes, stiffness, damping coefficient, distributions of the inertance coefficients, frequency spacing, and frequency response of the controlled structure. For purposes of further comparison, the optimum results of the TTMD and tuned mass damper‐inerter (TMDI) are also included into consideration. Results clearly demonstrate that the TTMDI outperforms both the TTMD and TMDI because of several advantages, particularly high effectiveness and broadband characteristics. Therefore, the TTMDI is deemed to be a broadband high effectiveness control device. Furthermore, the TTMDI only needs a linking dashpot and is capable of decentralizing a large inertance coefficient, thus showing its simplicity and easier implementation.
Summary
This paper proposes a novel high performance hybrid passive base‐isolated system integrating the base‐isolated system (BIS) with the tuned tandem mass damper inerters (TTMDI), referred to as ...the BIS+TTMDI. To reveal the interaction between two components and their integrated control performance, the proposed configuration is modeled by a simplified four degree‐of‐freedom model together taking the dynamic characteristics of the isolation system, TTMDI, and superstructure into inclusion. Employing the optimization criterion defined as minimization of the dimensionless variance of superstructure displacement relative to the ground and by resorting to the particle swarm optimization, the system parameters of TTMDI are tuned to get their best integrated control performance. Evaluations are in turn unfolded on the performance taking into diverse TTMDI inertial properties and different isolation layer characteristics account and robustness, to fully explore the effectiveness of reducing both the displacement and acceleration for the isolation layer and superstructure, the TTMDI's energy dissipation mechanism and capacity, evolution of stiffness and damping, stroke, and structural frequency response. Subsequently, the findings of the BIS+TTMDI in the frequency domain is further tested via the time history analyses using the real records including both near‐field with pulse and far‐field earthquakes. In two analysis domains, the integrated performance of the proposed BIS+TTMDI is compared not only to the BIS but also to the BIS+TMDI, as well as to the BIS+TTMD and BIS+TMD. Results confirm that the BIS+TTMDI is a high performance system, namely, with high control effectiveness, high robustness, highly smaller stroke, and drastically reduced damping demand.
