Vibration Control Of High-rise Buildings Research Articles

Bi-directional wind-induced vibration control of high-rise buildings using bi-directional rail variable friction pendulum-tuned mass damper

Flexible high-rise buildings are extremely vulnerable to wind, especially when synchronously subjected to alongwind and crosswind forces. In this scenario, acceleration-sensitive targets (such as delicate instruments) are at risk of damage. Moreover, occupant comfort and structural safety may be degraded due to excessive bi-directional vibrations. To resolve this problem, a bi-directional rail variable friction pendulum-tuned mass damper (BRVFP-TMD) is used to achieve optimal bi-directional wind-induced vibration control. The modeling of the BRVFP-TMD for bi-directional high-rise buildings under bi-directional winds was performed. Further, the physical interaction forces of the BRVFP-TMD with a multi-degree-of-freedom structure and the governing equations for the modal structure with the BRVFP-TMD were derived, with experimental results confirming the effectiveness of the linear variable friction force. For the BRVFP-TMD with a lightly damped structure, acceleration optimizations were conducted to obtain closed-form solutions for optimal parameters. However, the deployment position of the tuned mass damper (TMD) was found to degrade the optimal control performance significantly. Therefore, for the convenience of engineers, improved optimal solutions were obtained by considering the actual deployment position of the TMD and the influence of inherent structural damping. The stochastic linearization method was used to evaluate the effect of linear hysteretic damping (HD) with equivalent viscous damping (VD) in the field of random theory. Accordingly, a closed-form expression for the VD ratio was proposed to represent HD. Numerical verifications of a Chinese landmark (Canton Tower) subjected to bi-directional winds were assessed through time history and frequency decomposition analyses. The results verified the effectiveness, correctness, and necessity of the BRVFP-TMD; the improved optimal solutions were also confirmed. Compared with the closed-form solution, which neglects the deployment position of the TMD, and the classic TMD, the improved optimal solutions of the BRVFP-TMD demonstrated superior performance in mitigating both structural displacement and acceleration. The vibration reduction ratios achieved were 44.55% for the displacement at the top of the mast and 46.69% for the acceleration at the top of the main tower.

Experimental verification of seismic vibration control of high-rise buildings with friction-type multiple tuned mass dampers

In recent decades, tuned mass damper (TMD) devices have been implemented in numerous high-rise buildings in the world. The vibration of tall buildings caused by natural or man-made dynamic loading poses a challenge. In this study, to ensure structural safety and resident comfort, a friction-type multiple TMD (FT-MTMD) system was investigated and its ability to reduce the seismic response of high-rise buildings was evaluated. The proposed FT-MTMD system comprises multiple TMD units in a parallel arrangement and has a greater frequency bandwidth than a conventional TMD system. To address practical issues, a prototype FT-MTMD system was designed and fabricated to control a scale-down test model which has similar fundamental modal properties to a real 36-story building. Because of the nonlinearity of friction, the parameters of the FT-MTMD system were determined using a proposed optimal design method. First, a component test was conducted to ensure that the parameters of the FT-MTMD agreed with the designed values. Then, the FT-MTMD was installed on the long-period test model and its control performance was experimentally evaluated. Shaking table test results indicated that the FT-MTMD system favorably reduced the seismic response in the test model, indicating that the proposed optimal design method is reliable. A theoretical structure–MTMD model was also developed to simulate the system response with unsynchronized stick-slip motion of the FT-MTMD system. The predicted system response agreed well with the measured response. In addition, to avoid damage to the FT-MTMD system during a severe earthquake, a fail-safe device was employed to lock the TMD when its stroke reached the maximum allowable value.

Amplitude dependence of natural frequency and damping ratio for 5 supertall buildings with moderate-to-strong typhoon-induced vibrations

Modal parameters play a significant role in the wind-resistant design and vibration control of high-rise buildings. Results from previous studies demonstrate that the natural frequency and damping ratio of high-rise buildings usually exhibit nonlinear variation characteristics with the increase of structural amplitude. However, due to lacking relevant field measurements, the features of natural frequency and damping ratio for super-tall buildings under large wind-induced amplitudes have been less explored. This paper presents a field study on typhoon-induced structural responses of five supertall buildings whose structural heights all exceed 300 m. The peak acceleration responses at the measurement height of most buildings exceeded 10 cm/s2 (gal), with the maximum response reaching 20 gal. Two frequently used methods, i.e., the stochastic subspace identification (SSI) and random decrement technique (RDT) methods are utilized to compare and analyze the amplitude-dependent characteristics of target modal parameters. It is found that with the increase of wind-induced structural vibration amplitude, the fundamental natural frequency generally first decreased and then leveled off, while the damping ratio for the first-order mode of the buildings except the one equipped with a tuned mass damper (TMD) system first increased while then tended to decrease. More interestingly, the critical normalized structural vibration amplitude associated with the maximum damping ratio is found to be in the range of 10−4∼10−5, which agrees well with the theory of “critical tip drift ratio”. Potential explanations for the above phenomena are presented. Furthermore, the obtained results are further compared with existing statistical models, and associated discrepancies suggest the complexities of the dynamic features of supertall buildings.

Development of locally resonant meta-basement for seismic induced vibration control of high-rise buildings

High-rise buildings may suffer severe damage or even collapse when subjected to excessive vibrations during earthquake excitations. Suppressing seismic induced vibrations is of great significance to ensure the safety of these high-rise structures. Many vibration control techniques have been proposed in the past decades, but certain inherent limitations exist in these methods. Recent investigations in the field of solid-state physics have revealed that periodic structures, termed elastic metamaterials, can be used to manipulate the propagation patterns of acoustic/elastic waves. Waves are not able to propagate through the periodic structure when the frequencies of input waves fall within the bandgaps of the structure. This special characteristic has motivated researchers to develop meta-based techniques for structural vibration control. On the other hand, floating floor structure (FFS), in which the floor is isolated from the supporting beam, has been used to control the vibrations of buildings. Inspired by the periodic theory and FFS, in the present study, the conventional underground basement of high-rise building is modified to form a locally resonant meta-basement to block the propagation of seismic waves for mitigation of building vibrations during earthquake excitations. Firstly, the formation of bandgap of the proposed method is demonstrated through analytical study on the infinite number of unit cells and finite element modelling on the finite number of meta-basement. The influences of three key parameters of the meta-basement, i.e., the connecting spring stiffness, the number of meta-basement levels, and the parking ratio on the bandgap characteristics are then examined. Two design strategies of the meta-basement with the capability of reducing the seismic wave energy at frequencies corresponding to the vibration frequencies of the super-structure or reducing the seismic wave energy at its dominant frequency contents are proposed. Numerical simulations are carried out in both the frequency and time domains to evaluate the control effectiveness of the two design strategies on an example building structure. Results show that the proposed meta-basement can reduce the seismic responses of high-rise buildings and designing the meta-basement to mitigate the transmission of seismic wave energy at vibration frequencies of the super-structure is more effective to reduce building vibrations.

Two-level friction damping and its application for passive multi-functional vibration control of high-rise buildings

In recent years, the use of structural elements and/or entire structures with low internal damping are favoured with the increasing trend for unconventional design of structures and infrastructures that combine high functionality and increased aesthetics. One example is the advancement of high-rise buildings, which are built taller, more slender and with more spectacular designs compared to the past. In many of these cases, supplementary damping is included in the structural design by installing distributed passive damping devices, among which the friction damper has become popular due to its relative low cost, high reliability and high efficiency. The conventional friction damper, however, can only mitigate vibrations optimally with respect to a single deformation shape at a single vibration amplitude, which is not enough in cases where additional damping is required to mitigate different magnitudes of the excitation. Thus, the paper scrutinises the performance of the passive two-level friction damper, recently proposed elsewhere, in comparison to the conventional one-level friction damper, and assesses its application for multi-functional vibration control of a high-rise building. Specifically, this paper scrutinises the application and performance of the two-level friction damper in two simulation-based frameworks and ultimately: (i) evaluates and demonstrates the vibration performance of a dynamic system when equipped with this damper type, and (ii) investigates the application of this damper type for mitigation of both wind- and earthquake-induced vibration of a high-rise building. It is found that the optimal performance of the two-level friction damper is covering a larger vibration amplitude range compared to the conventional friction damper, which enabled the two-level friction damper to, in contrast to the conventional friction damper, successfully mitigate both wind- and earthquake-induced vibration in the application example. Based on the findings, it is concluded that the two-level friction damper is able to overcome some of the limitation, application-wise, connected to the amplitude dependence of the one-level friction damper.

Model reduction techniques for high-rise buildings andits reduced-order controller with an improved BT method

An AMD control system is usually built based on the original model of a target building. As a result, the fact leads a large calculation workload exists. Therefore, the orders of a structural model should be reduced appropriately. Among various model-reduction methods, a suitable reduced-order model is important to high-rise buildings. Meanwhile, a partial structural information is discarded directly in the model-reduction process, which leads to the accuracy reduction of its controller design. In this paper, an optimal technique is selected through comparing several common model-reduction methods. Then, considering the dynamic characteristics of a high-rise building, an improved balanced truncation (BT) method is proposed for establishing its reduced-order model. The abandoned structural information, including natural frequencies, damping ratios and modal information of the original model, is reconsidered. Based on the improved reduced-order model, a new reduced-order controller is designed by a regional pole-placement method. A high-rise building with an AMD system is regarded as an example, in which the energy distribution, the control effects and the control parameters are used as the indexes to analyze the performance of the improved reduced-order controller. To verify its effectiveness, the proposed methodology is also applied to a four-storey experimental frame. The results demonstrate that the new controller has a stable control performance and a relatively short calculation time, which provides good potential for structural vibration control of high-rise buildings.

Wind Power Generation Using Vibration Control of High-Rise Buildings on the Bearing

Wind Power Generation Using Vibration Control of High-Rise Buildings on the Bearing

Analysis on vibration control of a large-span pedestrian suspension bridge based on a multiple tuned mass damper system

Tuned mass damper is one of the commonly used passive control devices. It is the earliest used device in civil engineering control of vibration control of high-rise buildings and towering structures. For large-span pedestrian bridges, the pedestrian load spectrum covers many modalities of pedestrian bridges. It is difficult to achieve the expected results with a single tuned mass damper device. In order to obtain efficient damping, the multiple modes of a multiple tuned mass damper which may resonate under excitation are controlled. This chapter adopts the pedestrian suspension bridge over Dongtan River as the subject to arrange a multiple tuned mass damper system in the finite element model of the pedestrian suspension bridge, analyze the effectiveness of the multiple tuned mass damper system on the control of human-induced vibration of a large-span pedestrian suspension bridge, and discuss the vibration reduction effect of the multiple tuned mass damper system on the response to human-induced vibration of the pedestrian suspension bridge. The analysis shows that a multiple tuned mass damper system has a significant effect on controlling human-induced vibration of the pedestrian suspension bridge.

Vibration control of high-rise buildings for wind: a robust passive and active tuned mass damper

Tuned mass dampers (TMDs) have been installed in many high-rise buildings, to improve their resiliency under dynamic loads. However, high-rise buildings may experience natural frequency changes under ambient temperature fluctuations, extreme wind loads and relative humidity variations. This makes the design of a TMD challenging and may lead to a detuned scenario, which can reduce significantly the performance. To alleviate this problem, the current paper presents a proposed approach for the design of a robust and efficient TMD. The approach accounts for the uncertain natural frequency, the optimization objective and the input excitation. The study shows that robust design parameters can be different from the optimal parameters. Nevertheless, predetermined optimal parameters are useful to attain design robustness. A case study of a high-rise building is executed. The TMD designed with the proposed approach showed its robustness and effectiveness in reducing the responses of high-rise buildings under multidirectional wind. The case study represents an engineered design that is instructive. The results show that shear buildings may be controlled with less effort than cantilever buildings. Structural control performance in high-rise buildings may depend on the shape of the building, hence the flow patterns, as well as the wind direction angle. To further increase the performance of the robust TMD in one lateral direction, active control using LQG and fuzzy logic controllers was carried out. The performance of the controllers is remarkable in enhancing the response reduction. In addition, the fuzzy logic controller may be more robust than the LQG controller.

Telescopic columns as a new base isolation system for vibration control of high-rise buildings

In this paper, a new type of passive energy dissipating system similar to added damping and stiffness (ADAS) and triangular added damping and stiffness (TADAS) is proposed and implemented in the analytical model of a building with hybrid structural system in the structure's base which we call it; Telescopic column. The behavior and performance of a high rise R.C. structure equipped with this system is investigated and compared with conventional base isolation systems such as rubber isolator bearings and friction pendulum bearings. For this purpose a series of ground acceleration records of the San Fernando, Long Beach and Imperial Valley earthquakes are used as the disturbing ground motions in a series of numerical simulations. The nonlinear numerical modeling which includes both material and geometric nonlinearities were carried out by using SAP2000 program. Results show suitable behavior of structures equipped with telescopic columns in controlling the upper stories drifts and accelerations.

Optimum study on wind-induced vibration control of high-rise buildings with viscous dampers

In this paper, optimum methods of wind-induced vibration control of high-rise buildings are mainly studied. Two optimum methods, genetic algorithms (GA) method and Rayleigh damping method, are firstly employed and proposed to perform optimum study on wind-induced vibration control, six target functions are presented in GA method based on spectrum analysis. Structural optimum analysis programs are developed based on Matlab software to calculate wind-induced structural responses. A high-rise steel building with 20-storey is adopted and 22 kinds of control plans are employed to perform comparison analysis to validate the feasibility and validity of the optimum methods considered. The results show that the distributions of damping coefficients along structural height for mass proportional damping (MPD) systems and stiffness proportional damping (SPD) systems are entirely opposite. Damping systems of MPD and GAMPD (genetic algorithms and mass proportional damping) have the best performance of reducing structural wind-induced vibration response and are superior to other damping systems. Standard deviations of structural responses are influenced greatly by different target functions and the influence is increasing slightly when higher modes are considered, as shown fully in section 5. Therefore, the influence of higher modes should be considered when strict requirement of wind-induced vibration comfort is needed for some special structures.

309 塑性流動抵抗型ダンパの動的加力実験と実建物への適用

In recent years, research and development of various types of dampers were applied to several structures, such as buildings and large-scale industrial structures, in order to reduce their seismic responses during earthquakes. An elastomeric extrusion damper having its simple configuration was proposed as a large-capacity damper. The damper used un-valcanized rubber as its working fluid, and could obtain large damping forces by throttling plastic flow of rubber in a vessel. In this paper, dynamic tests were carried out for a full-size damper, which was designed to have a 500kN damping force at velocity input of 0.25m/s and could be used for vibration control of high-rise buildings and large-scale industrial facilities. From the experimental results, the load-displacement characteristic of the damper was found to have a rectangular shape with the rounded corners, and it was also confirmed that the damping force was proportional to the velocity raised to the power of 0.1107.

Output Feedback Sliding Mode Control for Bending and Torsional Vibration Control of 6-story Flexible Structure

We discuss bending and torsional vibration control of a 6-story flexible structure. In the case in which the vibration control of high-rise buildings is considered, it is necessary to design a controller which shows good control performances, and which is simply designed so that personnel expenses are reduced. To this end, we have applied a sliding mode control theory, which is one of nonlinear robust control theories. By adopting this theory, the control system may easily be designed in a very short time. However, since it is in few cases that each story is provided with a sensor, this controller is generally designed as a state feedback controller, and is difficult to realize a state feedback. Therefore, the sliding mode controller should be designed as an output feedback controller. Accordingly, we have designed two output feedback sliding mode controllers by using minimum error excitation method. The first controller is constructed with only nonlinear control inputs, and the second controller is constructed with both linear and nonlinear inputs. We have investigated their performances by numerical simulations and experiments. In this paper, design methods, control system design constraints, and characteristics in flexible structural control will be explained.

Vibration Control of High-Rise Buildings Using High-Damping Rubber Damper. 4th Report. Loading Tests of Full-Size Cylinder Type High-Damping Rubber Damper and Examination of Its Vibration Control Performance.

Many vibration control systems, which are divided into a mass damper system and a storey-installation damper system, for habitability or seismic-safety improvement in high-rise buildings have been developing in recent years. However, a passive energy absorbing system will be the most ideal devices if we consider to reduce the structural responses against the various levels of inputs such from traffic induced vibration to destructive vibration. This study has been developed the vibration control system of an energy absorbing type used the high-damping rubber as a vibration control material. We had already cleared experimentally and analytically that the high-damping rubber damper has stable damping performances in wide vibration area through the various loading tests and the shaking table tests. In this paper, the fundamental performances and the vibration control effects of the full size high-damping rubber damper which was made from the results up to this time is described.

Vibration Control of High-Rise Buildings Using High-Damping Rubber Damper. 3rd Report. Temperature Dependency and Durability of Cylinder Type High-Damping Rubber Damper.

A new type of high-damping rubber damper for vibration control of tall buildings has been being developed in this study. This paper describes the temperature dependency of the damper which will be an important problem in vibration control systems using high molecule material. The tests were carried out in two different conditions from the viewpoint of the temperature variation of vibration control material into the dampers. One is the variation of environmental temperature around the damper and the other is the self-generated heat in the damper which will be induced by the cyclic loading such as earthquake or wind. Moreover, the durability of damper was investigated by following tests; breaking test, static tests and cyclic loading tests under excessive shear strain amplitude. As the results, it was confirmed that the temperature dependency of the damper would not much affect to the energy absorbing characteristics even in the case of the practical use and the durability of the damper was highly enough against the large earthquakes by means of its strong adhesive characteristics.

Design of a mega-sub-controlled building system under stochastic wind loads

Vibration control of high-rise buildings under wind loads with application of the mega-sub-control method is studied in this paper. A building with a megasub-configuration consists of two major structural components - a megastructure as the main structural frame and several sub-structures for residential and/or commercial usage. The authors have previously proposed a ‘megasub-control method’ in which the sub-structures are designed to serve as vibration control dampers. The control objective is to suppress certain critical building responses such as inter-story drifts of the mega-structure for the purpose of structural safety and acceleration response of the sub-structures for the purpose of protecting contents and improving human comfort. The feasibility of this method has been explored by the authors in previous publications. In this study, the procedure of optimally designing dynamic parameters of a megasub-controlled building under stochastic wind loads is developed, together with two possible structural configurations which provide a mega-sub-control mechanism. The mega-structure of a mega-sub-building is modeled as a cantilever beam to retain the dominant bending mode characteristics of highrise buildings, and the sub-structure as a shear building to retain the shear mode. The fluctuating wind speed is modeled as a non-white random process in both time and space domains. The power spectral density (PSD) of critical building responses is obtained using the random vibration theory. The mean square value (MSV) of those responses, as functions of the dynamic parameters including the stiffness and damping ratio of the sub-structures, are evaluated from their PSD by numerical integration in the frequency domain. The optimal values of the dynamic parameters are determined by minimizing the MSV of certain critical building responses. An example building is used to demonstrate the design procedure and the numerical simulation of the response quantities in the time domain is carried out to verify the MSV of the building responses obtained from the random vibration theory in the frequency domain. The results show that the proposed design procedure is suitable to apply to a mega-sub-building with different sub-structural configurations. The MSV obtained from the random vibration theory in the frequency domain and from the numerical simulation in the time domain exhibit an excellent agreement. It is also found that the megasub-control method is robust in the sense that slight change in the dynamic parameters affects the building's performance very little. With the design procedure developed, and the corresponding favorable building response demonstrated, this paper has enhanced the feasibility of application of the mega-sub-control method to actual high-rise buildings for wind vibration suppression.

Vibration Control of High-Rise Buildings Using High-Damping Rubber Damper. 2nd Report, Loading Tests and Design Formula for Cylinder-Type High-Damping Rubber Damper.

This paper describes high-damping rubber damper used for vibration control of high-rise buildings. This damper aims at decreasing the wide vibration range from earthquake motion to wind-induced vibration input to a high-rise building. In general, highly molecular material like high-damping rubber has large temperature dependence of mechanics characteristics. In order to consider the dependences of the damper on the temperature, the test sample was enclosed in a constant-temperature oven to keep the temperature constant. The experimental results were compared with the design formula of the damper proposed in this study. The design formula enables to express the damping force characteristics of this damper qualitatively and quantitatively. Moreover, the damping characteristics of the damper was examined with the Voigt model.

Vibration Control of High-Rise Buildings Using High-Damping Rubber Damper. 1st Report. Shaking-Table Test and Response Analysis.

Research and development of a new type of high-damping rubber damper for high-rise buildings/structures to mitigate earthquake or wind-induced structural response is described in this paper. Tall buildings/structures can undergo excessive structural deflexions, at their resonant frequencies, due to excitation from strong earthquake motion or wind effects. Also, for weak earthquakes, which occur several times a year in Japan, or for weak wind, it is considered that the structural aseismic comfort will be strongly needed in the near future. The high-damping rubber damper developed in this study dissipates energy sufficiently, and the responses of the building are significantly reduced.