高层建筑非线性地震反应的智能控制

本文研究高层建筑非线性地震反应的振动控制,采用MR阻粘器作为控制装置,设计了减小高层建筑非线性地震反应的半主动控制策略,提出了半主动H∞控制律.对20层受控建筑进行了非线性反应的数值仿真分析.分析结果表明,本文设计的半主动控制策略能有效地抑制高层建筑的非线性地震反应.     

消能减震技术在大型体育场馆中应用的研究

消能减震技术作为建筑抗震的新技术，能有效吸收地震能量，降低建筑物振动反应。本文分别采用等效线性简化算法以及阻尼器与建筑结构的非线性分析方法，针对实际体育馆建筑结构抗震性能现状提出了加固方案，并对加固方案进行了计算分析。分析方法及结果可供现有类似结构的抗震改造加固借鉴参考。     

考虑多输入影响的高层建筑结构模型模糊控制

为提高地震作用下高层建筑结构模糊控制的减振效果,本文在两输入模糊控制的基础上,提出了考虑多输入影响的修正两输入模糊控制,对顶层设置AMD控制装置的12层钢框架模型结构进行模糊控制研究。首先,利用FCM聚类算法从初步模型得到的受控结构反应数据中提取模糊规则,设计模糊控制器;其次,利用Simulink建立了考虑多输入影响的修正两输入模糊控制系统并进行仿真分析;最后,进行了1∶8比例的高层建筑模型结构模糊控制振动台试验研究。仿真与试验结果均表明:考虑多输入影响的修正两输入模糊控制系统比普通两输入模糊算法的控制效果提高了约10%,对顶层位移反应峰值的控制效果达到70%左右,且易于实施。本文的研究为进一步提高结构振动模糊控制效果提供了新的思路和方法,可为主动控制工程应用提供参考。     

屋盖MR智能隔震系统对升船机地震反应的智能控制

升船结构很难采用常规的结构振动控制方法来抑制其顶部的地震反应,故提出利用MR智能阻尼器的屋盖MR智能隔震系统来减小升船结构顶部厂房的地震侧移反应和柱底的地震反应。MR智能阻尼器是利用磁流变液产生阻尼力的半主动控制装置,该装置具有机械构造简单,动力范围宽广,只需要较小的能量输入就能产生大的输出力,因此被证明能有效运用于土木工程结构来抵抗强烈地震和强风。本文阐述了MR阻尼器的力学性能,建立了屋盖MR智能隔震升船结构的控制方程,在此基础上实现MR模糊半主动控制。应用本文提出的方法对升船结构屋盖MR智能隔震系统进行仿真计算结果表明:模糊半主动控制使升船结构顶部层间位移和柱底弯矩均有明显的减小,能有效抑制升船结构顶部厂房的地震鞭梢效应。     

三维隔震振动台试验研究

震中大分量水平与竖向地震作用导致大量建筑结构破坏。目前,隔震系统仅能减小水平地震作用,而三维隔震系统可有效控制结构的竖向和水平反应而减轻地震灾害。由于三维隔震系统竖向和水平自振频率低,三维地震作用下,结构摇摆反应难以控制。为解决这一难题,设计了一种新型的三维隔震系统,该系统包括水平隔震层和竖向隔震层,抗摇摆装置安装在竖向隔震层中用于控制结构摇摆反应。为验证该三维隔震系统性能,对二层钢框架结构模型进行了振动台试验研究。振动台试验结果表明,三维隔震技术能有效减小上部结构响应,并大大提高建筑结构的抗震安全性。     

粘滞消能器在某框架楼中的减震分析

结构被动减振控制是通过在结构中合理设置被动消能装置,来有效地控制结构的振动响应,使结构在地震、大风或其他动力干扰作用下的各项反应值被控制在允许范围内。其中粘滞消能器在某框架楼中的应用分析结果显示该建筑结构的地震响应明显减小,对建筑结构起到了有效的减震控制。     

结构振动主动模态模糊控制算法减震效果研究

提出了结构振动主动模态模糊控制算法,可以减少所需要的模糊推理数量,使其处于可以接受的范围之内。建立了一栋20层结构地震动力反应振型模糊控制的分析模型,并利用Matlab语言编制了求解软件。计算结果表明:采用模态模糊控制算法可以达到满意的减震效果。只对第一模态控制就能达到较好的减震效果。增大控制力UA的大小,可以达到更好的减震效果。模态模糊控制算法明显地减少了多个状态变量之间模糊关系的判断以及状态变量和控制规则识别的运算。     

钢筋混凝土结构非线性阻尼地震反应谱研究

阻尼比对结构的地震反应有重要的影响,目前结构抗震设计阶段通常取阻尼比为常数,不能真实反映建筑物的阻尼机理。基于对钢筋混凝土建筑物非线性阻尼比的分析研究,通过数值分析,提出了建筑抗震设计反应谱的非线性阻尼比修正系数,建立了非线性阻尼比地震反应谱曲线。该曲线不仅考虑了设防烈度和场地条件对建筑物地震反应的影响,也可反映建筑物不同结构类型和结构振动过程中阻尼性能的变化对结构地震反应影响。非线性阻尼比地震反应谱曲线与现行建筑抗震设计规范中标准地震反应谱曲线之间能保持理论体系上的一致性,对工程设计具有一定的参考价值。     

半主动调谐质量阻尼器对非线性结构的减震控制

传统调谐质量阻尼器(TMD)具有对频率调谐敏感和对宽频带地震下的消能减震性能不佳等缺陷。强震作用下,建筑结构会进入非线性阶段。为了保护建筑结构在强震下的安全性并提高被动TMD(PTMD)对非线性结构的减震作用,本文研究了一种能够同时变频率变阻尼的半主动TMD(STMD)及复合控制算法。该STMD既可通过基于小波变换(WT)的调频算法实时改变单摆的长度以调节自振频率,又可基于主结构和TMD的振动信号进行阻尼系数的开关调换。对一10层非线性建筑结构进行算例分析,研究了该STMD对结构在地震激励下的弹塑性响应的控制作用,并与一优化的PTMD进行了减震效果对比。数值模拟中,对地震激励进行了幅值的缩小及放大以考察其对STMD减震作用的影响。研究结果表明：STMD对该非线性结构的弹塑性震动响应具有良好的控制效果,能够减小结构的塑性发展及残余位移,并提高PTMD的耗能能力。STMD能够有效地减小结构的顶层位移和层间位移,控制性能优于PTMD。     

基于优化模糊控制规则的磁流变阻尼减震结构地震反应分析

由于采用半主动控制的磁流变阻尼器减震结构存在非线性和时变等因素,精确数学模型的建立非常困难。模糊控制是一种比较合适的控制方法,但模糊控制的设计易受人类主观经验的影响而不甚完善,致使控制的效果受到影响。本文利用遗传算法提出一种优化模糊控制规则的新的控制算法,并对安装磁流变阻尼器的某3层钢筋混凝土结构进行了数值仿真,比较了无控结构、模糊控制结构及遗传算法优化模糊控制结构在地震作用下顶层的位移和加速度响应。结果表明:与人为经验设计的模糊控制相比,利用遗传算法优化的模糊控制可使结构顶层位移、加速度的控制效果均得到明显提高。     

Seismic analysis of benchmark building installed with friction dampers

The 20-storey steel building has been declared as seismically excited benchmark building by structural control community to compare various control strategy, such as active, passive, semi-active and combination thereof. In this study, dynamic behaviour of the benchmark building installed with friction damper is investigated. For evaluation of structural responses, the seismic excitations considered are El Cento, Hachinohe, Northridge and Kobe. The friction damper with numerical rectangular ideal elasto-plastic hysteretic model is proposed to be used for the analysis. The effectiveness of friction dampers for reduction of responses namely, displacement, acceleration, base shear and performance criteria stipulated in the benchmark problem is investigated. Since, the activation of friction damper depends on slip force, a parametric study is also conducted to investigate the optimum slip force of the dampers, which yield the minimum responses. Further, optimal placement of dampers, rather than providing the dampers at all the floor levels is also studied, to minimise the cost of the dampers. Numerical study is also carried out by varying the slip force of dampers along the height of the benchmark building. Results show that for appropriate slip force and optimum location number, friction dampers installed in benchmark building can effectively reduce earthquake-induced responses.     

Comprehensive nonlinear seismic performance assessment of MR damper controlled systems using virtual real‐time hybrid simulation

Magnetorheological (MR) dampers have gained significant attention in seismic mitigation of structural systems due to their distinguished characteristics such as inherent stability and minimum power requirements. Their performance in control of nonlinear structural response, however, has not been widely investigated. This paper provides comprehensive nonlinear seismic performance assessment of a three‐story benchmark structure equipped with a large‐scale MR damper using virtual real‐time hybrid simulation to efficiently capture the nonlinear behavior of the damper. The framework is first verified by means of available experimental results of an actual RTHS on the same structural system. A set of 12 earthquake ground motions, each one scaled to have 12 different intensities are then utilized to perform nonlinear dynamic analyses. An energy‐based adaptive passive‐on control strategy is proposed, and its performance is compared with passive‐on, passive‐off, and uncontrolled response of the structure in terms of interstory drifts shown by fragility curves, residual drifts, MR damper control force, and the ability to maintain a uniform interstory drift along the height of the structure.     

磁流体阻尼器半主动控制结构的地震反应分析

对磁流变阻尼器的性能及恢复力模型进行了介绍,并对其参数进行了设计,提出了基于经典线性最优控制算法和瞬时最优控制算法的半主动控制律.通过对一装有七个MR阻尼器的七层框架结构的地震反应分析表明,基于这两种控制算法的半主动控制律是非常有效的,并且该半主动控制方法能够有效地减小结构的地震反应.     

Semi‐active algorithm for energy‐based predictive structural control using tuned mass dampers

A novel semi‐active control algorithm is developed and numerically evaluated for the suppression of undesirable structural vibrations. The mechanical energy of the vibrating structure is considered as the primary variable influencing the control action. This intuitive strategy is proposed to realize improved control of structural vibrations. The numerical study conducted reveals that the proposed energy‐based predictive (EBP) algorithm can be implemented on vibration control applications. The energy imparted to the structure is also reduced due to the proposed algorithm. The influence of the parameters of the proposed semi‐active tuned mass damper is studied. Further, the application of the proposed strategy on a realistic structure is numerically demonstrated by implementing the algorithm for the wind response control of a 76‐story benchmark building. The results show that the EBP algorithm is a competitive semi‐active strategy. The robustness of the strategy is also evaluated considering uncertainties in the properties of the benchmark building.     

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.     

Adaptive control of base-isolated structures against near-field earthquakes using variable friction dampers

This paper investigates the effectiveness of two adaptive control strategies for modulating the control force of variable friction dampers (VFDs) that are employed as semi-active devices in combination with laminated rubber bearings for the seismic protection of buildings. The first controller developed in this study is an adaptive fuzzy neural controller (AFNC). It consists of a direct fuzzy controller with self-tuning scaling factors based on neural networks. A simple neural network is implemented to adjust the input and output scaling factors such that the fuzzy controller effectively determines the command voltage of the damper according to current level of ground motion. A multi-objective genetic algorithm is used to learn the shape of the activation functions of the network. The second controller is based on the simple adaptive control (SAC) method, which is a type of direct adaptive control approach. The objective of the SAC method is to make the plant, the controlled system, track the behavior of the structure with the optimum performance. Here, SAC methodology is employed to obtain the required control force which results in the optimum performance of the structure. For comparison purposes, an optimal linear quadratic Gaussian (LQG) controller is also developed and considered in the simulations together with maximum passive operation of the friction damper. The results reveal that the developed adaptive controllers can successfully improve the seismic response of base-isolated buildings against various types of earthquake.     

结构振动控制的新方法

首先对结构振动控制进行了分类,然后提出了耗能减震技术的新发展以及摩擦耗能减振技术的研究现状,最后列举实例进行了现有摩擦阻尼器的应用分析,得出摩擦阻尼器在实际结构中的应用势在必行的结论。     

Performance evaluation of an MR damper in building structures considering soil–structure interaction effects

Since the force generated by a magneto‐rheological (MR) damper has large nonlinearity, the performance of an MR damper is dependent on response characteristics such as frequency and amplitude. Soil–structure interaction (SSI) is generally known to have a large effect on the seismic response of a building structure. In this study, the performance of an MR damper in mitigating the seismic response of a building structure is evaluated considering the SSI effects. First, the performance variance of an MR damper due to the change of the structural natural period is investigated by constructing its normalized response spectrum through the numerical analysis of many earthquake wave records and the natural period of a structure. The variable friction force of an MR damper is normalized by the structural base shear force, and its amplitude and decrement of response are quantitatively evaluated. Then, the response characteristics of the SSI system due to the lengthening of the structural natural period and various soil conditions are numerically evaluated based on the response spectrum analysis. Finally, the numerical results with and without considering the SSI effects are comparatively evaluated for the building structure with an MR damper. The comparison results show that the SSI effect should be considered in order that the undesirable effect of an MR damper on the structural control would not be neglected. Copyright © 2007 John Wiley & Sons, Ltd.     

新型摩擦阻尼器的研究及其在建筑结构振动控制中的应用

探讨了一种新型耗能摩擦阻尼器的耗能原理及其在建筑结构振动控制中的应用。研究表明,该阻尼器除具有传统阻尼器的优点外,还克服了传统摩擦阻尼器只能提供恒定的摩擦力的缺点。同时,该阻尼器还可以利用振源信号进行反馈控制,因此增大了耗能能力,提高了减振效果。有限元仿真分析证明,该新型摩擦阻尼器应用在建筑结构上具有较好的减振效果。     

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。