地王大厦风振TMD主被动切换混合控制研究

本文采用调谐质量阻尼器对地王大厦这一高层建筑在风荷载作用下的顶点位移进行主被动混合控制，即508重现期风荷载作用下用TMD被动控制，1008重现期风荷载作用下切换为TMD主动控制。理论分析和计算表明，这种控制方式造价低，经济效果佳，以较小的能量输入可取得较优的控制效果。     

大连国贸大厦高层水箱风振控制研究及应用

本文针对一实际工程结构———大连国贸大厦,研究了风荷载作用下调液阻尼器的减振控制作用。首先建立了该结构的简化计算模型,利用Davenport谱给出了模拟风荷载。在大厦所处位置进行多次测量,得到实际风速样本。选取其中风速较大、过程平稳的样本,对实测样本和模拟样本的频谱进行比较,验证了模拟风荷载的合理性。文中将大厦顶层的生活水箱设计成可减小结构位移及加速度反应的控制装置TLD(tuned liqu id damper),根据不同工况进行数值计算,选出最佳方案,设计出可实际应用、并达到一定减振效果的减振水箱,以提高大厦在风荷载作用下的舒适度。     

TMD参数对高耸结构风振控制的影响

以电视塔为例，研究了被动TMD系统对高耸结构风振控制的效果和影响其控制效果的相应参数，然后对TMD参数进行了优化设计，得到了系统更加突出的控制效果。     

结构最优主动调谐质量阻尼器风致振动控制的研究

基于我国现行的风荷载规范,建立了在风荷载作用下结构-主动调谐质量阻尼器(ATMD)系统的动力方程。定义ATMD最优参数准则为:结构-ATMD系统的位移或加速度响应方差的最小化。ATMD有效性的评价准则为:设置ATMD结构的最小化位移或加速度响应方差与未设置ATMD结构的位移或加速度响应方差之比(分别称为位移和加速度减振系数)。根据上述准则,在频域内数值研究了结构自振频率、标准化加速度反馈增益系数、质量比对ATMD系统的最优参数(包括最优频率比和阻尼比)、有效性和冲程的影响。此外,为了比较的目的,论文同时考虑了结构TMD风致振动控制的情况。     

磁流变阻尼器对高层建筑风振舒适度的半主动控制分析

高层建筑风振舒适度的控制是结构抗风设计的一项重要内容。本文提出了磁流变阻尼器对高层建筑风振舒适度控制的一种设计方法。由于加速度是舒适度的判别标准，因此，首先通过对依据现行规范计算和用计算机模拟两种方法下得到的加速度进行比较，进而对模拟的脉动风荷载进行合理的修正，并以此作为抗风设计的依据；其次，根据磁流变阻尼器在不同位置时的控制效果，合理地布置控制装置，在此基础上，通过对加速度的有效控制来满足结构舒适度要求；最后，对磁流变阻尼器的参数进行合理的设计，达到优化的目的。     

H∞优化控制理论在半主动控制中的应用

着重研究了变阻尼半主动控制在降低结构振动响应中的控制效果，在确定可变阻尼的阻尼系数时采用了控制效果较好的H∞优化控制策略，并将这种控制策略与传统控制方法进行了比较，通过数值分析比较了被动控制、主动控、半主动控制情况下结构的最大相对位移与结构的最大绝对加速度响应。并通过分析得出如下结论：(1)在被动、主动、半主动控制方法中主动控制的控制效果最好；(2)对于刚性结构，增大结构的附加阻尼可以同时降低结构的最大相对位移和最大绝对加速度响应，应用被动控制能取得较为理想的控制效果，而半主动控制的控制效果是值得怀疑的，在应用时应慎重考虑；(3)对于柔性结构，增大附加阻尼在降低结构的最大相对位移响应的同时，却增加了结构最大绝对加速度响应，而采用半主动控制能够同时降低结构的最大相对位移和绝对加速度响应，半主动控制效果明显；(4)在柔性结构中采用半主动控制方法能取得与主动控制相近的效果；(5)由于H∞优化控制是对最坏情况下瞬时能量的优化控制，因此H∞半主动控制的控制效果要优于传统LQR控制。     

拱型结构振动控制的研究

本文将控制技术运用到拱型结构的振动控制中,运用单点和多点控制方法,将主动控制力表为位移,速度和加速度的线性函数,在频域内探讨了拱型结构某些关键部位加速度频率响应随地面运动频率变化情况,研究了主动控制参数对加速度响应的影响,并对带有主动控制装置的拱型结构在随机激励作用下的响应进行了分析,对拱型结构的振动控制给出了一些有益的看法。     

土木工程结构控制的某些装置和方法

本文系统介绍、评述了当前有关结构控制中的被动控制装置和主动线性结构控制方法的研究现状及存在问题，对有关控制理论方法和硬件设备的结构，性能做了清理和介绍，提出了下一步研究的方向，供今后研究工作参考、借鉴。     

两结构高效阻尼控制系统随机动力反应分析

对由高效阻尼装置(HEDMS)连接的两单自由度相邻结构在过滤白噪声激励下的相对位移响应进行了随机分析。在对阻尼装置滞变位移等价线性化的基础上，采用虚拟激励法计算结构响应的谱密度和互谱密度，研究了该阻尼装置各参数对位移响应方差的影响以及该装置的适用范围。     

基于加速度反馈的结构地震反应半主动MR阻尼控制试验

本文针对安装有半主动磁流变阻尼器（MR damper)的一座二层模型结构进行了抗震振动台试验研究，通过采用基于加速度反馈控制策略的两种半主动控制算法进行了在各种地震动作用下模型结构的半主动控制的抗震试验研究，并进行了Passive-on和Passive-off两种被动控制的试验研究。试验结果表明，MR阻尼器作为一种半主动控制装置可以有效地控制结构的峰值位移和均方差反应，且半主动控制对结构顶层的峰值位移和均方差的控制效果均优于两种被动控制方法。因此，本文提出的两种半主动控制算法都是有效的，并宜于实现。     

屋盖悬挑端加固减振试验研究

大跨网架屋盖挑檐部分风致响应较大,提出附加杆件、粘弹性阻尼器及粘滞阻尼器三种加固减振方法。设计制作正置四角锥体单元空间网架足尺子结构试验模型,基于带悬挑平屋盖风压分布风洞试验数据,对三种加固足尺子结构试验模型进行不同风向角下风荷载时程的加载。分析结构风致加速度与位移响应,结果表明:附加杆件加固后网架刚度增大,加速度响应增大,位移响应减小;附加粘弹性阻尼器,结构加速度与位移响应均降低;附加粘滞阻尼器,结构加速度响应减小,位移减小效果不明显。     

Multi‐objective optimal design of FLC driven hybrid mass damper for seismically excited structures

Structural vibration control using active or passive control strategy is a viable technology for enhancing structural functionality and safety against natural hazards such as strong earthquakes and high wind gusts. Both the active and passive control systems have their limitations. The passive control system has limited capability to control the structural response whereas the active control system depends on external power. The power requirement for active control of civil engineering structures is usually quite high. Thus, a hybrid control system is a viable solution to alleviate some of the limitations. In this paper a multi‐objective optimal design of a hybrid control system for seismically excited building structures has been proposed. A tuned mass damper (TMD) and an active mass driver (AMD) have been used as the passive and active control components of the hybrid control system, respectively. A fuzzy logic controller (FLC) has been used to drive the AMD as the FLC has inherent robustness and ability to handle the non‐linearities and uncertainties. The genetic algorithm has been used for the optimization of the control system. Peak acceleration and displacement responses non‐dimensionalized with respect to the uncontrolled peak acceleration and displacement responses, respectively, have been used as the two objectives of the multi‐objective optimization problem. The proposed design approach for an optimum hybrid mass damper (HMD) system, driven by FLC has been demonstrated with the help of a numerical example. It is shown that the optimum values of the design parameters of the hybrid control system can be determined without specifying the modes to be controlled. The proposed FLC driven HMD has been found to be very effective for vibration control of seismically excited buildings in comparison with the available results for the same example structure but with a different optimal absorber. Copyright © 2002 John Wiley & Sons, Ltd.     

Multiobjective optimal FLC driven hybrid mass damper system for torsionally coupled,seismically excited structures

In most of the research work on structural vibration control only two‐dimensional plane structural modelling has been considered, although only a few practical building structures can be modelled as planar structures. Therefore, these methods are not directly applicable to the majority of the practical building structures. This paper discusses the design of a multiobjective optimal fuzzy logic controller (FLC) driven hybrid mass damper (HMD) system for seismically excited torsionally coupled building structures. Floor acceleration and velocity information have been used as feedback to the fuzzy logic controller. A three branch tournament Genetic Algorithm has been used for the multiobjective optimal design of the FLC driven HMD system, where the minimization of the non‐dimensionalized peak displacement, acceleration and rotation of the structure about its vertical axis, have been as the three objective functions. The proposed multiobjective optimal fuzzy logic controller has been verified for an example problem reported in the literature. This HMD system consists of four HMDs arranged in such a way that the system can control the torsional mode of vibration effectively in addition to the flexure modes of vibration. Copyright © 2002 John Wiley & Sons, Ltd.     

Seismic performance evaluation of typical dampers designed by Chinese building code

Adding dampers is a commonly adopted seismic risk mitigation strategy for modern buildings, and the corresponding design procedure of dampers has been well established by the Chinese Building Code. Even though all types of dampers are designed by the same procedure, actual seismic performance of the building may differ from one to the others. In this study, a nine-story benchmark steel building is established, and three different and typical types of dampers are designed according to the Chinese Building Code to realize structural vibration control under strong earthquake excitation. The seismic response of the prototype building equipped with a viscoelastic damper, viscous damper and buckling-restrained brace(BRB) subjected to 10 earthquake records are calculated, and Incremental Dynamic Analysis(IDA) is performed to describe progressive damage of the structure under increasing earthquake intensity. In the perspective of fragility, it shows that the viscoelastic damper has the highest collapse margin ratio(CMR), and the viscous damper provides the best drift control. Both the BRB and viscoelastic dampers can effectively reduce the floor acceleration responses in the mid-rise building.     

增设节点阻尼器的外附钢框架结构抗震性能试验研究

提出一种组合型减震结构,由钢框架、节点阻尼器和原结构连接组成,外附钢框架将节点阻尼器连接在原混凝土框架结构上形成的增设节点阻尼器的外附钢框架结构,节点阻尼器的剪切滞回变形可以减小结构自身需要消耗的能量,从而提高原结构抗震性能。对原混凝土结构和增设节点阻尼器的组合型结构进行了的振动台试验。通过分析结构在不同地震波激励下的加速度和位移响应,得出楼层加速度和层位移的减震效果。研究结果表明:该结构体系在小震作用下通过提高结构刚度来增强其抗震性能;在大震作用下则可借助节点阻尼器的变形耗能来提升结构耗能能力,结构加速度减震系数达到53%,层间位移减震系数高达72%,验证了增设节点阻尼器的外附钢框架结构的减震效果。     

Experimental study of the semi‐active control of building structures using the shaking table

A magnetorheological (MR) damper has been manufactured and tested and a non‐linear model is discussed. The parameters for the model are identified from an identification set of experimental data; these parameters are then used to reconstruct the force vs. displacement and the force vs. velocity hysteresis cycles of the MR damper for the hysteretic model. Then experiments are conducted on a three‐storey frame model using impact excitation, which identifies dynamic parameters of the model equipped with and without the MR damper. Natural frequencies, damping ratios and mode shapes, as well as structural properties, such as the mass, stiffness and damping matrices, are obtained. A semi‐active control method such as a variable structure controller is studied. Based on the ‘reaching law’ method, a feedback controller is presented. In order to evaluate the efficiency of the control system and the effect of earthquake ground motions, both numerical analysis and shaking table tests of the model, with and without the MR damper, have been carried out under three different ground motions: El Centro 1940, Taft 1952, and Ninghe 1976 (Tangshan Earthquake in Chinese). It is found from both the numerical analysis and the shaking table tests that the maximum accelerations and relative displacements for all floors are significantly reduced with the MR damper. A reasonable agreement between the results obtained from the numerical analysis and those from the shaking table tests is also observed. On the other hand, tests conducted at different earthquake excitations and various excitation levels demonstrate the ability of the MR damper to surpass the performance of a comparable passive system in a variety of situations. Copyright © 2003 John Wiley & Sons, Ltd.     

Evaluation of the performance of a suspension isolation system subjected to strong ground motion

This study is concerned with a new isolation device called a Suspended Pendulum Isolation (SPI) system here. Particular attention is given to evaluate the dynamic behaviour of the system under substantial ground motions including the El Centro 1940, Hachinohe 1968 and Kobe 1995 earthquakes. Shaking-table tests have been carried out for a 4 25-scaled model comprising a test structure supported on the SPI system with lead damper. Several yield strengths for the lead damper are examined to investigate its properly designed dimensions. Experimental results show that the SPI system with lead damper has a substantial capability to decrease either peak acceleration or peak base (bearing) displacement responses for broad-band frequency excitations. It also confirms that maximum-storey drift index of isolated structure has been dropped to about one-sixth of its corresponding value at fixed-base condition under strong level of predominant excitation along with considerable decrease of peak acceleration. A non-linear analytical model for an MDOF shear building has been also developed by utilizing the fourth-order Runge–Kutta algorithm. Comparison of analytical and experimental time-history responses for all of the excitations indicates that there is a good agreement in both peak values and shape pattern of the results. Moreover, SPI with an appropriate yield strength of lead damper creates only a very small permanent displacement after strong excitation. © 1998 John Wiley & Sons, Ltd.     

A method for stochastic seismic response analysis of non-classically damped structures

A method to calculate the stationary random response of a non-classically damped structure is proposed that features clearly-defined physical meaning and simple expression. The method is developed in the frequency domain, The expression of the proposed method consists of three terms, i.e., modal velocity response, modal displacement response, and coupled (between modal velocity and modal displacement response), Numerical results from the parametric study and three example structures reveal that the modal velocity response term and the coupled term are important to structural response estimates only for a dynamic system with a tuned mass damper. In typical cases, the modal displacement term can provide response estimates with satisfactory accuracy by itself, so that the modal velocity term and coupled term may be ignored without loss of accuracy, This is used to simplify the response computation of non-classically damped structures. For the white noise excitation, three modal correlation coefficients in closed form are derived. To consider the modal velocity response term and the coupled term, a simplified approximation based on white noise excitation is developed for the case when the modal velocity response is important to the structural responses. Numerical results show that the approximate expression based on white noise excitation can provide structural responses with satisfactory accuracy~