考虑控制器拓扑的随机动力系统最优控制

在简要回顾几类结构控制模式的基础上,本文提出考虑控制装置最优布设与控制器参数优化的随机最优控制方法,将它们统一为物理随机最优控制的广义最优控制律。为有效地寻找每个序列工况的控制器最优拓扑和控制器参数,分别定义基于超越概率的层可控指标梯度最小准则和能量均衡最优准则。数值算例分析表明,采用广义最优控制律可以以最小的投资获得最大的控制效益。同时表明,按层可控指标梯度最小准则寻优,比先前按层可控指标最大准则寻优能更有效地收敛到目标性态。     

设置混合调谐质量阻尼器的高层建筑风振控制实用设计方法

结合GB 50009-2012《建筑结构荷载规范》中的等效静风荷载计算方法,研究设置主被动可切换的混合调谐质量阻尼器(TMD/ATMD)的规则高层建筑结构的风振分析与实用设计方法。将控制系统的风振控制效果按照风振响应方差相等的原则归结为对受控结构的附加等效阻尼比,推导了控制系统最优参数和附加等效阻尼比的计算公式,给出了惯性质量平均最大行程比、主动控制力和额定功率的简化计算方法;并讨论了主动/被动控制模式的切换准则。最后给出以风振控制Benchmark结构模型为对象的受控结构及混合调谐质量阻尼系统的设计算例。算例分析表明：建议的设计方法可以方便地进行受控结构响应分析和控制系统参数设计;混合调谐质量阻尼器可以有效减小设计等效静风荷载和结构的动力响应。     

可变阻尼结构的非线性半主动控制算法

对于安装连续可调粘滞阻尼器的工程结构,直接以可变阻尼为控制量,则受控结构可由一双线性系统来表示,基于线性二次型(LQR)最优控制,该文提出了一种非线性半主动控制算法,该算法需要求解Lyapunov矩阵方程。以3层剪切型受控结构为例,探讨在不同的可变阻尼器最大粘滞阻尼系数与支撑刚度组合下,控制算法对结构地震响应的减震效果,并与控制器阻尼系数始终取为最大值的被动控制效果作了对比。     

最小控制合成算法在结构振动控制中的应用

将模型参考自适应控制方法引入结构减震控制领域中,基于"最小控制合成算法(MCS)"的自适应控制理论,推导了建筑结构地震反应自适应控制的基本方程。提出了以地震能量降低模型为最优控制模型,设计并研究了该模型的自适应控制器。以地震能量降低模型的MCS自适应控制方法,对一个三自由度受控结构和天兴洲大桥MR磁流变阻尼器进行仿真分析。仿真结果表明:受控结构响应能够很好的跟踪参考模型响应,自适应控制器可以明显减小结构的地震响应。     

大型海上风力发电高塔随机最优减震控制

考察了基于结构动力可靠度的调谐液体柱形阻尼器(TLCD)参数优化设计方法,并用于风-地震联合作用及地震作用下海上风力发电高塔系统的随机最优控制。文中,采用Kane动力学-有限元一体化模型,建立了TLCD-结构整体系统方程。基于概率密度演化理论的极值分布方法,给出了基于可靠度的TLCD参数优化设计方法及程序解答。在数值算例中,采用随机谐和函数和物理随机风场模型分别模拟随机地震动和随机风荷载,通过对优化的受控系统进行随机反应分析与可靠度分析,比较了不同控制准则和约束条件下TLCD的减震控制效果。研究表明基于可靠度的随机最优控制方法是可行的。     

磁流变阻尼器在基础智能隔震建筑中的研究

针对橡胶隔震垫作为一种被动控制装置,存在最优控制范围窄的局限性。将磁流变阻尼器与橡胶隔震垫相结合,组成智能基础隔震系统应用于结构振动控制中,数值模拟分析了在地震力作用下原结构,普通隔震结构,隔震层附加MR阻尼器在Passive—off状态,Passive—on状态和磁流变阻尼器半主动智能状态下结构的反应。试验结果表明,结构在磁流变阻尼器半主动智能状态下控制效果最优,能有效克服被动隔震最优控制频带窄的缺点,其相对一般被动隔震装置,能同时减小隔震层位移,上部结构层间位移和各层最大加速度。     

基于刚度-阻尼器调谐质量阻尼器(SD-TMD)新模型策略的性能评价

利用导出的设置基于刚度一阻尼器调谐质量阻尼器(SD-TMD)结构和SD-TMD的传递函数，建立了SD-TMD结构系统的动力放大系数。于是，SD-TMD最优参数与有效性的评价准则为：设置SD-TMD结构最大动力放大系数中最小值的最小化。而SD-TMD冲程的评价准则为：SD-TMD动力放大系数的最大值。基于土述的两个评价准则，研究了刚度比R对SD-TMD性能(最优参数、有效性和冲程)的影响。为比较，同时考虑了传统TMD(即R=0的SD-TMD)的数值结果。     

半柔性悬挂减振结构体系地震反应分析

针对一种新型高层建筑半柔性悬挂结构体系提出阻尼减振控制的方案。首先,阐述了结构体系构建方案及优越性;其次,以主体结构的时程响应最大值最小为控制目标,对粘滞流体阻尼器的阻尼系数进行优化分析;最后,基于最优的阻尼器参数,对半柔性悬挂减振结构与普通悬挂抗震结构进行了时程对比分析。结果表明:半柔性悬挂减振结构能够有效地消弱结构的峰值响应;存在最优的阻尼系数使得主体结构的顶点位移和基底剪力动力响应最小;悬挂楼段保持较小层间位移,有效发挥了各层阻尼器的效率,保护了非结构构件。     

结构增强调谐质量阻尼器控制研究

提出了结构增强调谐质量阻尼器(ETMD)装置。新装置是在调谐质量阻尼器(TMD)的基础上,在质量块与地基之间设置一个附加粘滞阻尼器而构成。将ETMD最优参数的评价准则定义为:设置ETMD的结构均方根位移(解析式)的最小值的最小化。在频域内评价了附加阻尼对ETMD控制结构位移响应的最优参数、有效性和冲程的影响,并与TMD装置进行比较。数值结果表明,ETMD的振动冲程控制明显优于TMD。     

连接Kelvin阻尼器的对称双塔楼结构被动控制研究

将连接阻尼器的对称双塔楼结构耦合为单个连接着Kelvin型阻尼器的2-DOF（degree of freedom）体系,推导了耦合结构体系的运动微分方程并基于能量最小原理求出了连接阻尼器的优化参数解析解。参数化分析表明结构各层频率比、质量比和刚度比是影响阻尼器控制效果的重要参数。对于一个给定的对称双自由度体系,存在最优的Kelvin阻尼器阻尼参数解析解使得结构的位移峰值响应有最小值,同时从结构的自振特性也会影响结构最终的控制效果。最后,通过数值算例,分别讨论了塔楼多自由度体系在地震激励下的位移时程、结构振动能量和层间位移角,验证了该文所提Kelvin阻尼器优化参数解析表达式对控制带底盘对称双塔楼结构动力响应的有效性。     

粘弹性阻尼器参数设计及位置优化实用方法

粘弹性阻尼器是减振被动控制中一种十分有效的耗能减震装置.本文系统地阐述了粘弹性阻尼器用于结构抗震控制的设计方法，根据粘弹性阻尼器的耗能原理友抗震规范方法提出了粘弹性阻尼器位置优化实用方法，比较了粘弹性阻尼器在不同位置布置下的减震效果，并为粘弹性阻尼器几何参数及位置确定提供了实用可行的设计过程。     

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.     

A new operating strategy for economizer dampers of VAV system

The paper proposes a new operating strategy for the outdoor, discharge, and recirculation air dampers of the economizer in VAV system, called split-signal damper control strategy. The strategy controls the outdoor air by only one damper while keeping the remaining dampers full open. The discharge or recirculation air damper is modulated to control the amount of outdoor air introduced into the system while keeping the two remaining dampers full open. Since at least two dampers are always kept fully open during the occupied times, the strategy can provide a minimum static pressure drop in economizer dampers and results in minimum energy use in return and supply fans. An additional advantage is that the proposed strategy prevents reverse airflow through the discharge air damper of a VAV system that uses a volume matching control strategy. The proposed strategy along with the existing strategies such as the three-coupled dampers used in most existing system and the two-coupled dampers are evaluated on an existing system using 1-year long measured data set, along with an economizer damper model developed and validated in this paper. The simulation results show that the annual energy savings in supply and return fans of an existing system, compared to the traditional strategy of three-coupled dampers, are 12% and 5%, respectively.     

Optimization layout of viscous dampers and its application in retrofitting of a high-rise steel structure

阻尼器优化布置是结构减震设计过程中的重要环节，通常需要通过多次动力响应计算来完成。为此，提出了一种通过结构静力分析确定阻尼器合理布置位置的方法，并能够快速计算出优化方案的附加阻尼比。将该方法应用于一栋位于日本东京都新宿区29层钢结构建筑的减震加固设计中，分析了该建筑的强震观测系统在日本“311地震”中采集到的部分楼层加速度时程数据，并基于分析结果验证了所建立的非线性数值分析模型的可靠性。采用所提方法对结构进行减震加固，得到双向共64个阻尼器的优化布置方案及其附加阻尼比，并通过动力方法对结果进行了验证。同时针对长周期及长持时特性的地震波，对减震结构进行动力弹塑性时程分析，评估其抗震性能。分析结果表明：减震优化方案的减震效果明显，结构整体地震反应和构件损伤较非减震方案都大大减小；减震优化方案有效改善了高层钢结构楼层变形不均匀的情况，层间位移角均满足小于1/100的性能要求；通过减震优化后大部分钢支撑和钢梁的塑性率都降低至小于1。     

黏滞阻尼器的优化布置及其在高层钢结构加固中的应用

阻尼器优化布置是结构减震设计过程中的重要环节,通常需要通过多次动力响应计算来完成。为此,提出了一种通过结构静力分析确定阻尼器合理布置位置的方法,并能够快速计算出优化方案的附加阻尼比。将该方法应用于一栋位于日本东京都新宿区29层钢结构建筑的减震加固设计中,分析了该建筑的强震观测系统在日本“311地震”中采集到的部分楼层加速度时程数据,并基于分析结果验证了所建立的非线性数值分析模型的可靠性。采用所提方法对结构进行减震加固,得到双向共64个阻尼器的优化布置方案及其附加阻尼比,并通过动力方法对结果进行了验证。同时针对长周期及长持时特性的地震波,对减震结构进行动力弹塑性时程分析,评估其抗震性能。分析结果表明：减震优化方案的减震效果明显,结构整体地震反应和构件损伤较非减震方案都大大减小;减震优化方案有效改善了高层钢结构楼层变形不均匀的情况,层间位移角均满足小于1/100的性能要求;通过减震优化后大部分钢支撑和钢梁的塑性率都降低至小于1。     

Performance analysis of supply and return fans for HVAC systems under different operating strategies of economizer dampers

HVAC systems and associated equipment consume a relatively large fraction of total building energy consumption, a significant portion of which is attributed to fan operation. The operation of economizer dampers when installed can cause high energy consumption in fans if they are not functioning in proper and optimal manner. This will mainly be due to the potential high pressure drops through those dampers and associated high total pressures that should be developed by supply and/or return fans. It is then necessary to ensure that a proper strategy to operate optimally the economizer dampers is implemented with minimum fan energy use. The paper examines several operation strategies of the economizer dampers and investigates their effects on the performance of both the supply and return fans in HVAC system. It also discusses a new operating strategy for economizer dampers that can lead to lower fan energy use. The strategies are evaluated by simulations for a typically existing HVAC system. Several factors such as the building locations, system characteristics, resistance in the duct where the dampers are installed, supply air temperature and economizer control, and minimum ventilation requirements are also considered during the evaluations. The results show that the way of the economizer dampers been controlled has a significant effect on fan performance and its energy use. The proposed strategy if properly implemented can provide fan energy saving in the range of 5-30%, depending mainly on the number of hours when the system operates in the free cooling mode, damper characteristics, and minimum outdoor air.     

Optimal placement of metallic dampers for seismic upgrading of multistory buildings based on a cost‐effectiveness criterion using genetic algorithm

In this paper, an optimal placement methodology for metallic dampers is proposed to upgrade the seismic performance of multistory buildings. Most previous studies on optimal damper placement (ODP) problems have been focused on minimizing the seismic responses, whereas the present study aims to utilize the minimum total cost of dampers to achieve a prescribed level of seismic response. To this end, the optimization objective is constructed based on a cost‐effectiveness criterion, and the optimization constraint is defined based on a desired level of seismic response. An improved integer‐coded genetic algorithm is presented for solving the ODP problem. A 16‐story shear building is illustrated to verify the proposed optimal placement methodology. It is shown that the proposed methodology can be used to achieve the predetermined performance level while minimizing the retrofitting cost. Moreover, different algorithms, objective functions, and levels of accuracy on the optimization are also compared. Finally, a two‐step optimization approach is proposed for achieving better placement schemes with less computational efforts.     

基于极点配置算法的黏滞阻尼器优化设计

为克服常用极点配置算法的局限性,提出基于实模态空间解耦的极点配置算法,该算法求得的反馈增益矩阵中位移反馈增益始终为零,符合黏滞阻尼器特性。基于该反馈增益矩阵采用等效最优控制法进行参数优化设计,并提出基于阻尼器耗散能量的位置优化设计方法。在上述研究的基础上给出了黏滞阻尼器优化设计流程,并以某20层实际结构进行数值模拟,分析结果表明,被动控制系统性能与对应主动控制系统的性能相近,达到预期效果,验证该设计流程的有效性与正确性。