MOGA-Based Structural Design Method for Diagrid Structural Control System Subjected to Wind and Earthquake Loads

An integrated optimal structural design method for a diagrid structure and control device was developed. A multi-objective genetic algorithm was used and a 60-story diagrid building structure was developed as an example structure. Artificial wind and earthquake loads were generated to assess the wind-induced and seismic responses. A smart tuned mass damper (TMD) was used as a structural control system and an MR (magnetorheological) damper was employed to develop a smart TMD (STMD). The multi-objective genetic algorithm used five objectives including a reduction of the dynamic responses, additional stiffness and damping, mass of STMD, capacity of the MR damper for the integrated optimization of a diagrid structure and a STMD. From the proposed method, integrated optimal designs for the diagrid structure and STMD were obtained. The numerical simulation also showed that the STMD provided good control performance for reducing the wind-induced and seismic responses of a tall diagrid building structure.     

调频气压液柱阻尼器减振控制研究

调频气压液柱阻尼器（TLCGD）是一种从调频液柱阻尼器发展而来的新型而有效的结构减震装置。在U／V形阻尼器液柱上加上封闭式气压不仅增加了它的使用范围,使频率扩大到5Hz,并且提高了结构的有效阻尼。通过该装置在高层建筑和桥梁上的运用,U／V形调频气压液柱阻尼器能有效地控制水平为主的结构动力反应,而扭转调频气压液柱阻尼器（torsional tuned liquid column gas damper,TTLCGD）是一种能控制结构扭转为主的阻尼器。     

Optimal parameters for tall buildings with a single viscously damped outrigger considering earthquake and wind loads

Tall buildings suffer from low inherent damping and high flexibility. Therefore, a core-outrigger system is often used to stiffen such buildings. A modified form, known as the damped outrigger system, wherein vertically oriented dampers are installed between outriggers and perimeter columns, has been recently developed to supplement the damping. This paper studies the efficacy of a viscously damped outrigger system through dynamic analysis of a 60-story tall building subjected to nonconcurrent earthquake and wind excitations. Two ground motion sets (100 accelerograms) are used for the former and wind tunnel test data for the latter. Effects of three building parameters, namely, (i) the core-to-column stiffness ratio, (ii) the outrigger location, and (iii) the damper size, on the dynamic characteristics and seismic and wind responses are evaluated. Effects of damper nonlinearity on seismic and wind responses are also investigated considering energy-equivalent nonlinear viscous dampers. Finally, the optimum values of these parameters are determined. For example, the optimum outrigger location is found to be between $0.6H$ to $0.9H$, where $H$ is the height of the building. The results also show that the damped outrigger system significantly outperforms the conventional one for seismic excitation, and it is very effective in reducing the wind-induced floor accelerations, provided the parameters are chosen appropriately.     

Vertically distributed multiple tuned mass dampers in tall buildings: performance analysis and preliminary design

This paper investigates the structural performance of vertically distributed multiple tuned mass dampers (MTMDs), which can save valuable occupiable space near the top of tall buildings, control the first as well as higher mode responses and be installed more easily because of smaller tuned mass damper (TMD) masses. Vertically distributed MTMD theory is presented. With this theory, the effectiveness of vertically distributed MTMDs along the building height is predicted using simplified models, compared with the conventional TMDs installed near the top of tall buildings. Vertically distributed MTMDs are designed for a typical 60‐storey tall building subjected to representative dynamic wind loads, and their performance is measured. The results of these studies show that TMDs can be distributed vertically along the building height without substantial loss of their effectiveness. Considering their advantages over the conventional system, vertically distributed MTMDs possess a high potential of practical applications for tall‐building motion control. Copyright © 2009 John Wiley & Sons, Ltd.     

A combined tuned damper and an optimal design method for wind‐induced vibration control for super tall buildings

The wind‐induced vibrations of super tall buildings become excessive due to strong wind loads, super building height and high flexibility. Tuned mass dampers (TMDs) and tuned liquid column dampers (TLCDs) have been widely used to control vibrations for actual super tall buildings for decades. To fully use both the economic advantage of the TLCD system and the high efficiency of the TMD system, an innovative supplemental damping system including both TLCD and TMD and called combined tuned damper (CTD), which can substantially decrease the cost of the damper, was proposed to control the wind‐induced vibrations of tall buildings. The governing equations are generated for the motion of both the primary structure and the CTD and solved to anticipate the dynamic response of the CTD‐structure system. Moreover, an optimal design method of human comfort performance is proposed, in which the life cycle cost of the damper‐structure system is considered as the quantitative index of the performance. The life cycle cost includes the initial cost, the maintenance cost and the failure cost. The failure cost can be calculated using the vibration‐sensation rate model, which is based on the Japanese code AIJES‐V001‐2004. Copyright © 2016 John Wiley & Sons, Ltd.     

Seismic design and assessment for midrise buildings equipped with damped-outrigger system

The damped-outrigger system has been proposed to improve the performance of conventional outrigger systems in controlling the structural seismic response by increasing the damping and stiffness. The purpose of this study is to demonstrate the effectiveness of using damped-outrigger systems in midrise buildings and provide engineers with a comparison between conventional structural systems such as moment resisting frame (MRF) and buckling-restrained braced frame (BRBF) in proposing the most suitable structural system. In this study, the buckling-restrained brace and viscous damper are adopted as the energy dissipation devices in the damped-outrigger system. A total of 48 midrise numerical models with various building heights and structural systems are analyzed using nonlinear response history analysis and incremental dynamic analyses. The analysis results show that the midrise buildings equipped with a damped-outrigger system with either viscous damper or buckling-restrained brace (BRB) can reach similar and even better seismic performance when compared with the BRBF; it also reduces the structural responses by around 30% for the maximum roof drift and acceleration responses when compared with MRF. The analysis results could provide a reference for structural engineers when selecting suitable lateral force resisting systems for midrise buildings.     

设置粘弹性阻尼器钢结构高层建筑抗震抗风设计的实用方法

本文提出了设置粘弹性阻尼器的钢结构高层建筑抗震抗风设计的实用方法。文中在导出了设置粘弹性阻尼器高层钢结构的有效阻尼比计算公式的基础上，建立了设置粘弹性阻尼器结构抗震设计反应谱的调整公式和抗风设计风振系数、脉动增大系数的调整公式。从而使设置粘弹性阻尼器钢结构高层建筑的抗震抗风设计可在我国《高层民阻建筑钢结构设计与施工》规程的基础上进行。应用本文方法对设置粘弹性阻尼器的５０层全钢缔构超高层建筑──首都规划大厦主楼的抗震抗风设计的结果表明：粘弹性阻尼器是一种十分有效的减振耗能构件，它有效地减小了结构构件的地震设计内力和结构横风向的风振加速度。对于设置粘弹性阻尼器的高层钢结构，本文提出的抗震抗风设计方法是一种对结构工程师应用十分方便的实用设计方法。     

Optimal vertical configuration of combined energy dissipation outriggers

The damped outrigger system emerged as an improvement of the conventional outriggers with the aim to provide supplemental damping and to contribute to the vibration control in super tall buildings where this system is usually applied. In addition to viscous dampers (VDs), buckling‐restrained braces (BRBs) have also been employed as energy dissipating members in outriggers. Nevertheless, the combined use of outriggers with VDs and BRBs in the same structure has not yet been studied. Such combination can contribute to achieve an effective multiperformance design of super tall buildings. This paper presents a study whose main objective was to determine the optimal vertical combination of two types of energy dissipation outriggers to control the seismic responses of a 9‐zone super tall model structure. Outriggers with VDs (OVDs) and outriggers with BRBs (OBRBs) were placed at the different zones of the structure considering all the possible combinations and in configurations of up to four outriggers. The effects of these combinations on the seismic performance of the structure were studied through parametric analysis and optimization methods. This form of the outrigger system is defined in this paper as combined energy dissipation outrigger system. The results indicate that when two energy dissipation outriggers are used, the combination of OBRB plus OVD shows superior seismic performance compared with other double‐outrigger configurations. In addition, the results show that the locations of OVDs and OBRBs play an important role in the structure behavior; it was found that it is more beneficial to place OBRBs above OVDs.     

Influence of soil‐structure interaction on performance of a super tall building using a new eddy‐current tuned mass damper

Tuned mass dampers (TMDs) can be used as vibration control devices to improve the vibration performance of high‐rise buildings. The Shanghai Tower (SHT) is a 632‐m high landmark building in China, featuring a new eddy‐current TMD. Special protective mechanisms have been adopted to prevent excessively large amplitude of the TMD under extreme wind or earthquake loading scenarios. This paper presents a methodology for simulating behavior of the new eddy‐current TMD that features displacement‐dependent damping behavior. The TMD model was built into the SHT finite element model to perform frequency analysis and detailed response analyses under wind and earthquake loads. Furthermore, soil‐structure interaction (SSI) effects on wind and seismic load responses of the SHT model were investigated, as SSI has a significant impact on the vibration performance of high‐rise buildings. It was found that SSI has more significant effects on acceleration response for wind loads with a short return period than for wind loads with a long return period. Some of the acceleration responses with SSI effects exceed design limits of human comfort for wind loads with shorter return periods. As to the seismic analyses, it was found that SSI slightly reduces the displacement amplitude, the damping force, and the impact force of the TMD.     

设置磁流变阻尼器的高层钢框架支撑体系的地震反应研究

磁流变(MR)阻尼器是一种性能十分优秀的减振装置,具有构造简单、调节驱动容易和反应迅速等优点,能有效减小工程结构的地震反应和风振反应,具有广阔的应用前景。本文研究了安装MR阻尼器的高层钢结构框架支撑体系的抗震性能。在介绍了MR阻尼器力学模型的基础上,推导了MR阻尼器-支撑框架系统的地震反应基本方程,并且采用了基于最优主动控制力的“开关-耗能”半主动控制策略对MR阻尼器实施控制。应用本文方法对一栋20层的高层钢结构进行了模拟计算,结果表明:安装了MR阻尼器的框架支撑体系的抗震性能明显优于纯框架支撑体系,是一种简单、方便和有效的减振系统。     

Multi-objective fuzzy control of smart base isolated spatial structure

Base isolation systems are used widely to reduce the dynamic responses of structures subjected to a seismic load. Recently, research has been conducted actively on smart base isolation systems that can effectively reduce the dynamic responses of isolated structures without accompanying increases in the base drifts. On the other hand, control performance of smart base isolation systems for spatial structures has not attracted significant attention. This study examined the dynamic response reduction capacity of a smart base isolation system for a spatial structure subjected to seismic excitation. MR dampers and low damping elastomeric bearings were used to compose a smart base isolation system, and its vibration control performance was compared with that of the optimally-designed, lead-rubber bearing (LRB) isolation system. A fuzzy controller was used to effectively control the spatial structure with a smart base isolation system. The dynamic responses of the spatial structure with an isolation system conflicted with the base drift. Therefore, these two responses were selected as the objective functions to apply a multi-objective genetic algorithm to optimize a fuzzy controller. The numerical simulation results showed that the smart base isolation system proposed in this study can reduce drastically the base drifts and seismic responses of the example spatial structure compared to the optimally designed LRB isolation system.     

Proposed robust tuned mass damper for response mitigation in buildings exposed to multidirectional wind

The most common device for control of tall buildings under wind loads is the tuned mass damper (TMD). However, during their lifetimes, high‐rise and slender buildings may experience natural frequency changes under wind speed, ambient temperatures and relative humidity variations, among other factors, which make the TMD design challenging. In this paper, a proposed approach for the design of robust TMDs is presented and investigated. The approach accounts for structural uncertainties, optimization objectives and input excitation (wind or earthquake). For the use of TMDs in buildings, practical design parameters can be different from the optimum ones. Nevertheless, predetermined optimal parameters for a primary structure with uncertainties are useful to attain design robustness. To illustrate the applicability of the proposed approach, an example of a very slender building with uncertain natural frequencies is presented. The building represents a case study of an engineered design that is instructive. Basically, due to its geometry, the building behaves differently in one lateral direction (cantilever building) than the other (shear building). The proposed approach shows its robustness and effectiveness in reducing the response of tall buildings under multidirectional wind loads. In addition, linear‐quadratic Gaussian and fuzzy logic controllers enhanced the performance of the TMD. Copyright © 2012 John Wiley & Sons, Ltd.     

Study of a new type of replaceable coupling beam in reinforced concrete shear wall structures

It has been found from the past earthquakes that the reinforced concrete coupling beams in tall buildings easily suffer severe damage, which are very difficult to be repaired. To solve this problem, a new type of replaceable coupling beam with a combined damper installed in the middle was proposed in this study. The combined damper consists of an I‐shaped steel beam with multiple low‐yield‐point steel webs paralleled to each other and multiple layers of viscoelastic material bonded between multiple steel plates. The design method of the new replaceable coupling beam was introduced first. Cyclic loading tests on the combined damper were conducted to examine its mechanical behavior. To verify the effectiveness of the new replaceable coupling beam in resisting wind and seismic excitations, two high‐rise building structures, one with traditional coupling beams and the other with the proposed replaceable coupling beams, were designed, and the responses of two structures under the wind and the earthquake were compared with the aid of software Perform‐3D. Compared with the structure with traditional coupling beams, both of the seismic performance and the wind resistance capability of the structure with the proposed replaceable coupling beams are improved significantly.     

Adaptive fuzzy controller for active tuned mass damper of a benchmark tall building subjected to seismic and wind loads

Active tuned mass dampers (ATMDs) are one of the most effective solutions for mitigation of destructive effects of earthquakes and strong winds in tall buildings. In order to achieve optimal performance, these systems are designed and tuned to mitigate effect of either wind or earthquake excitation. However, due to different frequency contents and intensities of wind and earthquake excitations, which will cause contrasting structural modes stimulation, the ATMD designed for one of these disturbances may not work optimally for the other one. This paper addresses a methodological simulation approach for adaptive control design of ATMDs in tall buildings located in regions with high level of seismic activity and recurrent strong winds. For this purpose, a multi‐objective adaptive genetic‐fuzzy controller is proposed for the control of an ATMD of a benchmark 76‐story building subjected to wind load and earthquake disturbances. Simulation results reveal that the optimal ATMD designed for earthquake disturbance does not work adequately for wind load disturbance and vice versa. Furthermore, the proposed adaptive controller has superior performance in suppressing base shear and inter‐story drifts induced by wind load and earthquake excitations. Copyright © 2013 John Wiley & Sons, Ltd.     

高层建筑地震反应的分散最优迭代学习控制研究

针对地震作用下高层建筑结构的振动控制方法进行研究,引入分散控制的策略,将线性二次型最优控制(LQR)与迭代学习控制(ILC)算法原理相结合,提出分散最优迭代学习控制(Decentralized OptimalIterative Learning Control,DOILC)算法并应用于高层结构振动控制中。对某20层钢结构Benchmark结构模型进行数值计算与分析,结果表明,采用分散控制策略的DOILC算法与传统集中控制策略一样可以有效地抑制结构地震反应,相对于集中控制的单一失效分散控制系统的可靠性更强且数据实时处理效率大为提高。     

旋转惯容阻尼伸臂控制体系减震性能研究

旋转惯容阻尼器(rotation inertia damper,RID)具有质量小、阻尼力大的特点,应用于伸臂结构体系时必须考虑其转动惯量的影响。通过研究RID工作机理,推导了RID伸臂控制体系的振动微分方程,并提出了该体系的地震响应简化算法;考虑RID转动惯量影响,研究了结构各参数与地震响应的关系及其对减震效果的贡献。结果表明：RID伸臂控制体系的地震响应简化算法计算结果合理,与有限元法结果吻合较好;RID的质量参数对伸臂位置及阻尼参数的最优值影响甚微,而且对结构地震响应的影响也可忽略;外柱刚度将显著影响伸臂位置与阻尼器参数的最优值,而且当外柱刚度较大时有利于RID的性能发挥;RID伸臂控制体系具有良好的减震性能,即使在RID质量参数较大的情况下,也能保证其阻尼力在等效力中起主导作用。     

液体黏滞阻尼器在超高层结构上的抗震抗风效果和经济分析

为了保护地震及大风环境下的高层和超高层建筑,加设液体黏滞阻尼器是目前被工程界广泛认同、发展最为迅速、最为有效的结构振动保护方案。综合介绍国内外安装液体黏滞阻尼器的7座高层建筑,对阻尼器的安置方式、减振结构的抗震(振)效果、相关规范以及经济性进行评述。其中墨西哥Mayor大楼、美国波士顿大楼是世界工程界成功应用耗能减震装置的经典案例,银泰中心、盘古大观是我国首批使用阻尼器进行减振控制的超高层建筑,对这些工程采用的计算分析方法,结构抗震设计进行汇总,并提供相关建议和意见,供设计者参考。近期美国几位学者在一座42层钢筋混凝土结构的概念设计中,提出采用阻尼器替代剪力墙体系进行抗震设计的理念,对这一高层建筑工程的抗震新方向进行介绍,引为参考。     

拟负刚度磁流变智能隔震系统振动台试验研究

为研究拟负刚度控制算法及磁流变智能隔震系统的有效性和适应性,将自主研发的最大出力为10kN的磁流变液阻尼器(MRFD)安装在隔震层中心,并选取4条有代表性的远近场地震波,峰值加速度由0.1g~0.9g逐步增大,分别对普通隔震结构、输入电流为0A和1A的被动控制结构以及采用基于位移的拟负刚度(DPNS)控制算法的智能控制结构进行振动台试验。通过对结构响应和阻尼器响应的对比分析,研究拟负刚度控制算法的减震效果和磁流变智能控制系统的耗能特性。结果表明：恒定电流为0A的被动控制可同时降低上部结构反应和隔震层位移,但是减震效果有限;恒定电流为1A的被动控制对隔震层位移降低效果明显,但是在多遇地震及远场地震作用下放大了上部结构反应;DPNS控制可同时降低隔震层位移和多遇、设防地震甚至罕遇地震作用下上部结构的反应,且适应于不同的地震动特性;试验中控制系统存在的时滞效应使得DPNS控制力在多遇、设防地震作用下具有较小值,同时罕遇地震作用下具有较强的耗能能力。     

Reduction of vibration on a cantilever Timoshenko beam subjected to repeated sequence of excitation with magnetorheological outriggers

This paper deals with the statistical effects of an outrigger system on a cantilever beam under seismic excitation. The nonstationary random approach is employed to simulate seismic events. The Timoshenko beam approach is used to model the frame‐core tube linked at a point of its length by the damped outriggers, therefore are connected vertically two magnetorheological damper devices. The peak root‐mean‐square values of displacement responses is employed as a best measure effective to specify the optimal locations of outriggers according to different vibration modes. To evaluate the performance of the control system, the control algorithm based on Lyapunov stability theory is adopted to seek the input voltage leading to the reduction of vibration.     

Reduced order control for wind‐induced vibrations of tall buildings

The design of a structural control system for a tall building may not be easy owing to the large number of degrees of freedom involved. Obviously, it is much easier to design a structural control system for the reduced‐order system than for the full‐order system. Model reduction is thus useful when control systems are implemented in civil engineering structures. A reduced‐order modelling technology for vibration control of wind‐excited tall buildings is presented and its performance is studied. The important issues associated with wind‐induced vibrations, model condensations and reduced‐order control are addressed. Finally, a numerical example, a tall building with an active tuned mass damper or a passive tuned mass damper, is given to show the efficiency of the reduced‐order control technique. Copyright © 2003 John Wiley & Sons, Ltd.