Passive Structural Vibration Control Research Articles

Enhanced vibration absorption of plates with circular metasurface composed of lossy acoustic black hole subunits

Metasurfaces and acoustic black holes (ABHs), as two kinds of emerging structures exhibiting extraordinary performances in steering and trapping waves, respectively, both have attracted extensive attention of researchers due to their potential applications in vibration control. However, studies combining the merits of them are rarely reported. In this paper, we propose a lossy circular ABH metasurface (LCAM) composed of gradient ABH subunits pasted with damping layers to realize the enhanced omnidirectional vibration absorption of plates in broadband, which is attributed to the introduced multiple reflection effect in the lossy ABH subunits. The phase shifts of the lossy ABH subunits are derived by using the transfer matrix method and integral method, and the effective loss factors are obtained through the effective medium theory. Based on the theoretical analyses, the LCAM is designed, and the results of simulations and experiments show that the designed LCAM realizes enhanced omnidirectional vibration absorption of the plate. The LCAM is applied to plates with different dimensions and boundary conditions to show its strong adaptability. Our design improves the ABH effect by taking advantages of the multiple reflection effect in metasurfaces, which provides an effective method for passive structural vibration control.

Experimental and Numerical Study of Energy Dissipation Components of a New Metallic Damper Device

PurposeThe novel metallic damper device for passive vibration control of structures, which is designed primarily for seismic protection of buildings, is described in this paper. It consists of the base plate, fixed into foundation, with two concentric cycles of vertical components and a middle steel activating plate anchored to the isolated structure. During an earthquake, the middle steel activating plate moves together with main structure causing bending of vertical components. Seismic energy is absorbed due to plastic deformation of the vertical components of the damper. The performance of various vertical components, the key elements of the novel damper is studied in this paper. The advantages of this type of damper reflect in its ability to adapt its own features depending on the intensity of the earthquake and that it has equivalent characteristics in every horizontal direction due to rotational symmetry.MethodsSixteen experimental tests of the vertical components of the damper, were conducted to obtain their hysteretic behaviour. Numerical models using the finite element method and the Abaqus/Standard software were developed, validated and verified with experimentally obtained results.ResultsThe experimental results show significant energy absorption of the vertical components of the novel damper. Numerical models can be used in further research instead of expensive experimental tests.ConclusionsThe vertical components of the novel damper possess extraordinary hysteretic performance. If the components of the energy dissipation device are properly designed for maximum displacements, the device is not expected to suffer heavy damage or total failure during earthquakes.

Fixed and Base Isolated Framed Structures: A Comparative Study

Necessity of constructing multi-storied buildings is increasing these days. But they are more prone to severe damage due to earthquakes. Base isolation is one of the most powerful tools pertaining to the passive structural vibration control technologies. The structure above the ground, is separated from the effects of earthquake forces by introducing a mechanism that helps the structure to hover. This project deals with analysis of 10 storey RCC, Steel and Composite structures of different shapes with and without base isolation in various seismic zones by Response Spectrum Method using ETABS software. Lead rubber bearings designed as per UBC97 was used for base isolation. Plus shape was found to be most suitable for base isolation for RC structure, whereas for steel and composite structures rectangular and hollow shapes were found suitable. It was also observed that concrete structure performs best when base isolated, compared to other structures.

Adaptation of a Deep Liquid-Containing Tank into an Effective Structural Vibration Control Device by a Submerged Cylindrical Pendulum Appendage

Due to a high proportion of impulsive liquid mass and low inherent damping, liquid-containing deep tanks, such as conventional overhead water tanks, are generally not considered for design as tuned liquid dampers (TLDs) for passive vibration control of structures under lateral excitation. This paper presents a novel concept to convert deep tanks into effective vibration control systems through the incorporation of a submerged cylindrical pendulum appendage (CPA). The CPA is placed in the impulsive liquid zone of the tank and its oscillating frequency is tuned to the dominant frequency of the primary structure. When laterally excited, the primary structure transfers vibrational energy to the CPA, thereby setting it into oscillation. The motion of the CPA is opposed by the drag exerted by the surrounding liquid on it, which leads to dissipation of the vibrational energy. This particular design utilizes impulsive liquid mass in the energy dissipation mechanism, while allowing fluctuation in the liquid level in the upper region of the tank, thereby fulfilling the functional requirements of the tank. In this paper, the mathematical model and working principle of the deep tank with CPA (DT-CPA) damper are developed. The equations of motion of a two degree-of-freedom (2-DOF) structure-damper system are derived. The design of the DT-CPA damper is illustrated considering an example structure and the performance of the damper is examined by subjecting the structure-damper system to pre-recorded seismic base excitations. The sensitivity of the performance of the proposed damper to tuning ratio is further studied. Results indicate that the DT-CPA damper is effective in controlling structural vibrations and its performance is comparable to that of a conventional tuned mass damper (TMD) and even slightly superior to that of a conventional TLD system of the shallow tank configuration. The proposed concept thus holds potential for the utilization of deep tanks as energy dissipation devices with minimal interference to their usual functionality.

Flow Damping Devices in Tuned Liquid Damper for Structural Vibration Control: A Review

The tuned liquid damper (TLD) is an attractive option of passive structural vibration control due to distinct advantages of low installation and maintenance costs and easy amenability to design modifications. However, as it has low inherent damping, flow damping devices (FDDs) such as nets, screens, baffles, poles, floating objects, etc., are incorporated in the TLD to enhance its energy dissipation capacity. FDDs induce additional damping by providing hydraulic resistance to the sloshing liquid in the TLD. Each type of FDD has its own specific advantages and disadvantages and it would be beneficial to have a state-of-the-art comparative and comprehensive review of the work that has been carried out on different types of FDDs. This is the focus of the current paper. The present review would help in the assessment of the most suitable FDD for a particular TLD application. An overview of real implementations of TLD-FDD systems in various structures worldwide is provided. Directions of research for further development of FDDs are also identified.

The role of viscoelastic damping on retrofitting seismic performance of asymmetric reinforced concrete structures

The primary purpose of this research is to improve the seismic response of a complex asymmetric tall structure using viscoelastic (VE) dampers. Asymmetric structures have detrimental effects on the seismic performance because such structures create abrupt changes in the stiffness or strength that may lead to undesirable stress concentrations at weak locations. Structural control devices are one of the effective ways to reduce seismic impacts, particularly in asymmetric structures. For passive vibration control of structures, VE dampers are considered among the most preferred devices for energy dissipation. Therefore, in this research, VE dampers are implemented at strategic locations in a realistic case study structure to increase the level of distributed damping without occupying significant architectural space and reducing earthquake vibrations in terms of story displacements (drifts) and other design forces. It has been concluded that the seismic response of the considered structure retrofitted with supplemental VE dampers corresponded well in controlling the displacement demands. Moreover, it has been demonstrated that seismic response in terms of interstory drifts was effectively mitigated with supplemental damping when added up to a certain level. Exceeding the supplemental damping from this level did not contribute to additional mitigation of the seismic response of the considered structure. In addition, it was found that the supplemental damping increased the total acceleration of the considered structure at all floor levels, which indicates that for irregular tall structures of this type, VE dampers were only a good retrofitting measure for earthquake induced interstory deformations and their use may not be suitable for acceleration sensitive structures. Overall, the research findings demonstrate how seismic hazards to these types of structures can be reduced by introducing additional damping into the structure.

Dynamic Response of Tall Building with Base Isolation Subjected to Earthquake Forces

In the fast-paced contemporary world, new inventions with rapid construction techniques came across usually built to resist the lateral forces. Among them, the demand for tall buildings has put a revolutionary impact on society. In this study, base isolation as an earthquake resisting design technique was utilized which substantially dissociate a superstructure from its substructure and increase flexibility resisting on the ground vibration areas by providing the different types of base isolators. Lead rubber bearing (LRB) isolator is a passive structural vibration control technique. In this research study, seismic behaviour of tube in tube system steel tall building in square, circular, hexagonal, and octagonal plan configurations with varying frame sections with and without LRB base isolation was analyzed for the comparative analysis on the basis of base shear, overturning moment, time period, storey displacement, storey drift and storey acceleration according to IS 1893 (part 1):2016 and UBC 1997 Earthquake code in E-TABS software by non-linear time history analysis. From the results, Octagonal shape was found to be the best option for tall buildings whereas the hexagonal shaped building showed poor performance during an earthquake.

An elastoplastic bracing system for structural vibration control

This paper presents and investigates a new elastoplastic bracing system for passive vibration control of structures. It consists of a deformable elastoplastic metallic core comprising four Arcs around a central Ring and, therefore, the Bracing system is called the “AR-Brace”. Each arc is firmly attached tangentially to the central ring, then to the adjacent arc and finally to a corner of a structural panel, even directly or through a rigid arm. Different design variations of the AR-Brace could be obtained, by means of controlling the construction material and dimensions/thickness of its core, to passively adapt/tune the provided working ranges of stiffness/damping to specific requirements. In this work, some AR-Brace designs were studied to evaluate their efficiency. The device was thoroughly characterized mechanically using finite elements simulations and then modeled mathematically using the Bouc-Wen hysteresis model. The ability of the AR-Brace to control structural vibration and other vibration-dependent responses was investigated via numerical case studies under real and synthetic dynamics excitations. It was found that the displacement-based AR-Brace achieves a good balance between the added lateral rigidity and the provided damping, which was reflected in a remarkable mitigation of the undesirable effects of dynamic excitations, even at moderate levels of supplementary damping by the device.

Adaptive Negative Stiffness Device based nonconventional Tuned Mass Damper for seismic vibration control of tall buildings

Adaptive Negative Stiffness Device (ANSD) has been developed recently for passive vibration control of structures. ANSD emulates negative stiffness behavior (by exerting force toward the direction of motion) to a structure, so that, the combined structure-ANSD system shows smooth elasto-plastic force-deformation behavior with virtual yielding at target (“engaging”) displacement. The device has been studied analytically and its behavior has been demonstrated experimentally in simply supported bridge model and in Single Degree of Freedom (SDOF) structure considering limited input excitations. However, efficient and cost-effective exploitation of true potential of ANSD deserves further studies. With this being the eventual goal, in this study, we explore the performances of ANSD in seismic vibration control of a tall building by implementing a nonconventional Tuned Mass Damper (TMD) with drift control. In absence of a methodology for choice of ANSD parameters in literature, reported till date, we employ a tuning criteria for nonconventional TMD, on which the drift control is imposed as a constraint, given the special significance of drifts in tall buildings. The criteria of tuning and drift control are shown to be mutually conflicting and an algorithm is presented to address the same. Simplifying assumptions are made to develop the tuning criteria in presence of nonlinearity in ANSD and P−δ nonlinearity in tall building. A Reduced Order Modeling (ROM) approach for the building-ANSD system is developed to facilitate the algorithmic computations. Robustness of our design approach is shown under an acceptable level of detuning of TMD and near fault pulse type motions. Comparative assessment with a conventional design approach is presented to show the improvements. A step by step illustration of the developed methodology is briefly touched on in context of modern performance based approach. The study is a first step toward the possible utility of ANSD in controlling seismic vulnerability of tall buildings.

An inerter-enhanced nonlinear energy sink

Abstract This short communication proposes a novel nonlinear energy sink (NES) equipped with an inerter for passive vibration control of structures and presents the results related to the performance evaluation of this device. NESs are considered to be robust and effective passive control devices that can resonate in a broadband fashion. The configuration of the proposed nonlinear energy sink-inerter (NESI) is that of a traditional NES with an inerter between the device’s physical mass and a fixed point. Through the conversion of relative translational motion to rotational motion, the inerter is capable of providing an effective mass effect to the NESI. The optimum design values of the proposed device are achieved through a numerical search and the effect of the inerter on the response of the primary structure is presented. It was found that the effectiveness of the NESI can be substantially increased, compared to the NES, by using increasingly large values of inertance. As these results can be achieved by utilizing an inerter with a small physical mass, the NESI has potential to provide similar or better structural control performance as a NES that has more physical mass.

Parametric Study of Pounding Tuned Mass Damper Based on Experiment of Vibration Control of a Traffic Signal Structure

AbstractIn the last few years, a new type of passive damper, the pounding tuned mass damper (PTMD), has been proposed and studied for passive structural vibration control. Experiments and numerical...

Multistorey Residential Building with Base Isolation Method Using SAP

Residential homes are of exceptional significance after any natural calamity which encompass earthquake. The structural and non-structural additives need to stay operational and secure after earthquake. So you can mitigate the impact of earthquake at the structure the bottom isolation method is the splendid opportunity as a seismic protecting system. The primary concept of base isolation gadget is to lessen the earthquake brought on inertia forces by using growing the fundamental length of the structure. Base isolation is one of the most effective tools of engineering concerning the passive structural vibration control technologies. It is supposed to allow a building or non-building shape to continue to exist a probably devastating seismic impact thru a right preliminary design or next changes. In some instances, software of base isolation can improve each a structure's performance and its seismic sustainability notably. he behaviour of multi-storey building of ordinary and abnormal configuration beneath earth quake is complex and it varies of wind masses are assumed to behave concurrently with earth quake loads. On this paper a residential of multi-storey constructing is studied for earth quake with base isolation approach using SAP 2000.

Proposal of optimum tuning of semiactive TMDs used to reduce harmonic vibrations based on phase control strategy

Tuned mass dampers (TMDs) are a well-established technology for passive structural vibration control involving harmonic vibrations. Some design issues are critical to guarantee the proper functioning of the device, in particular, the adequate tuning and the adequate space to accommodate the TMD stroke. With regard to the first aspect, semiactive TMDs were proposed as an alternative means of correcting the vibrating frequency of the device by adding a semiactive element between the TMD and the structure. In this case, several control strategies have been proposed, among which phase control has proven to lead to excellent results. However, in the framework of this control approach, the minimization of the structure displacements is often used as the main objective of the control, as the relative displacements of the TMDs mass are considered a secondary issue, which nevertheless may be a crucial aspect in some applications. In this context, this paper proposes a strategy to optimally tune the semiactive TMD, taking into account a balance between the level of the reduction of the structural response and the amplitude of the TMD stroke. The optimal tuning is found by minimizing the system stationary mechanical energy. The problem is formulated as an optimization process, and the corresponding results are presented and discussed.

Advanced computational design of shared tuned mass-inerter dampers for vibration control of adjacent multi-story structures

Inerters are a novel type of mechanical actuation devices that are able to produce large inertial forces with a relatively small mass. Due to this property, inerters can provide an effective solution to the main drawbacks of tuned mass-dampers and, consequently, they are gaining an increasing relevance in the field of passive structural vibration control. In this paper, a computational design strategy for inerter-based vibration control schemes is presented. The proposed approach combines a computationally effective reduced-frequency H∞ cost-function and a constrained global optimization solver to design different configurations of a shared tuned mass-inerter-damper system for the seismic protection of a multi-story two-building structure. To assess the effectiveness of the obtained configurations, the frequency characteristics and the seismic response of the interstory drifts and interbuilding approaches are investigated with positive results.

EARTHQUAKE RESISTANT TECHNIQUES AND ANALYSIS OF TALL BUILDINGS

The tall buildings are more flexible than the shorter buildings and they are sensitive to a different frequency range in the earthquake excitation. The earthquake success of tall buildings is reinforced by studies using average properties of earthquake and typical properties of tall buildings and there are no special earthquake hazards that arise simply as a consequence of height. The purpose of this paper is to discuss about different analysis methods, base isolation and soil structure interaction. Analysis method is used for a large variety of tall building configurations comprising slabs, beams, columns, foundations, walls, etc. Base isolation is a collection of structural elements which should substantially separate a superstructure from its substructure resting on a shaking ground which protects the integrity of building or non-building structures. It is one of the most powerful equipment’s of earthquake engineering which uses the passive structural vibration control technologies. Soil Structure Interaction is the process in which the response of the soil influences the motion of the structure and the motion of the structure influences the response of the soil. General goal of the Soil Structure Interaction analysis is to calculate seismic response of structure bases on seismic response of free field.

COMPARISION OF BUILDING FOR SESMIC RESPONSE BY USING BASE ISOLATION

Throughout historic time Earthquakes are one of the natural hazards that occur due to sudden violent movement of earth’s surface which causes damage to property, especially to man-made structures . Base isolation is one of the most powerful tools of earthquake engineering pertaining to the passive structural vibration control technologies. The application of the base isolation techniques to protect structures against damage from earthquake attacks has been considered as one of the most effective approaches and has gained increasing acceptance during the last two decades. This paper present three dimensional nonlinear time history analysis is performed on r/c building by the use of computer program SAP 2000 v12.0.0. The dynamic analysis of the structure has been carried out and the performance of the building with and without isolator is studied. The main objective here is to make seismic response control by providing Isolators and comparing between the fixed based and isolated base building. Rubber bearing and Friction pendulum bearing are used

Effect of pseudoelastic hysteresis of shape memory alloy springs on the aeroelastic behavior of a typical airfoil section

The literature on aeroelasticity includes studies on the use of smart materials as sensors and actuators in vibration control problems. Although different smart materials are available, shape memory alloys have received growing attention in aerospace applications. The hysteretic response of shape memory alloys exhibiting pseudoelasticity provides energy dissipating and damping capabilities for these materials, and therefore, the effectiveness of the pseudoelastic behavior of shape memory alloys has been investigated for passive structural vibration control. However, its effect on the aeroelastic behavior of lifting surfaces has not been covered in the literature. Hence, this article addresses the modeling and analysis of a 2-degree-of-freedom typical aeroelastic section with shape memory alloy springs introduced through the pitch degree of freedom. A state-space model is employed for the simulations of the coupled system, and a two-state approximation to Theodorsen aerodynamics is used for the determination of the aerodynamic loads. The effects of the hysteretic behavior of the shape memory alloy springs on the aeroelastic behavior of the typical section are investigated at the flutter boundary and at post-flutter regime.

Optimal design of distributed tuned mass dampers for passive vibration control of structures

SUMMARY The distributed tuned mass damper (DTMD) system consists of multiple tuned mass dampers, which are designed to suppress the undesirable structural vibration over a bandwidth centered at a particular tuned frequency. In this study, an innovative practical approach to optimally design the DTMD system has been proposed. Comparisons were made between the optimal DTMD system, obtained based on the proposed design approach, and those using the conventional design approach. The superior performance and robustness of the optimally designed DTMD system based on the proposed approach compared with that based on the conventional approach have been demonstrated through illustrative examples. It has been shown that the proposed design approach provide a simple, clear, and straightforward way to effectively attain the optimum parameters of the DTMD system. Copyright © 2014 John Wiley & Sons, Ltd.

Structure isolation in order to reduce vibration transfer from the subsoil

Vibrations caused by road or railway vehicles running on surface or underground roads or rail tracks spread through the subsoil into surrounding building structures. These vibrations usually pose no threat to the safety of the structures, but they may limit the use of devices sensitive to vibrations in the buildings. An elastic foundation for the whole structure on a compliant rubber layer inserted into the foundation structure is a solution that restricts the transfer of vibrations into the buildings. The reinforced concrete structure of a building is used as an example here to illustrate the effi ciency of using a rubber layer in the footing bottom in order to reduce the propagation of vibrations into the building below the level observed in a non-isolated building structure when loaded by vibrations induced by traffi c. Vibrations propagate into the surroundings of the traffi c line through the geological environ- ment and act as technical seismicity, which loads the buildings in the vicinity. The histories of measured vibrations were used as loads applied to a modelled building structure at the foundation base. This article discusses ways of implementing vibration isolation in the foundation structure of a building in order to reduce the fl ow of vibrations into the protected part of the structure. For this model, the predicted vibrations in the individual storeys were shown and were com- pared with the level of excitation vibrations on the foundation base. The dynamic effects of subsurface traffi c propagating through the ground environment into the ambient buildings of urban agglomerations have been acquiring ever increasing impor- tance. Construction fi rms try to use the areas in the proximity of underground lines because of their lucrative location, usually for residential construction. It is these structures erected in the proximity of underground tunnels or directly above them in the case of shallow tunnels that are threatened by vibrations from underground traffi c. These vibrations propagate as non-stationary vibrations to the foundations of buildings in the vicinity of their source. The nature and magnitude of the vibrations caused by technical seismicity (1-4) depend not only on the proximity and the nature of the source of the vibrations but also on the local geological conditions and on the structure of the affected building. Due to its tuning, the building structure usually amplifi es or, in better cases, reduces the effects of technical seismicity. Vibro-base isolation is an effective method for reducing the vibration level of the protected structure as a whole with reference to its foundation types (plate, piles, strips, etc.) (1, 5-9). Base isolation is one of the most powerful passive structural vibration control technologies in earthquake engineering. It is meant to enable a building or some other structure to survive a potentially devastating seismic (or in our case technical seismic) impact through suitable initial design or subsequent modifi cations. In some cases, the application of base isolation can considerably raise both the seismic performance and the lifetime of a structure.

Direct evaluation of the equivalent linear damping for TLCD systems in random vibration for pre-design purposes

Passive control of structural vibrations has received in recent years a great attention from researchers concerned with vibration control. Several types of devices have been proposed in order to reduce the dynamic responses of different kinds of structural systems. Among them, the Tuned Liquid Column Damper (TLCD) proved to be very effective in reducing vibration of structures. Since the increasing use of TLCDs in practical realizations, this paper aims at developing an approximate formulation, by means of a statistical linearization technique, able to estimate the parameters of a structure equipped with a TLCD subjected to random loads for pre-design purposes. Moreover, it is shown that results obtained via Monte Carlo approach on the non-linear system are in good agreement with those obtained by means of the proposed formulation.