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。     

设置钢阻尼器钢结构的有限元分析

借助ABAQUS有限元软件,对设置钢阻尼器的钢结构进行了地震动荷载作用下的有限元分析,得出钢阻尼器能为结构提供附加抗侧刚度和附加阻尼,耗散输入的地震能量,保护主体结构,减震效果显著的结论。     

多维地震作用下非对称结构利用"双功能"软钢阻尼器减震设计

深入探讨了多维地震动作用下消能减震偏心结构的动力反应,建立了消能减震偏心结构的计算方法和动力方程。编制MATLAB程序,对一装有"双功能"软钢阻尼器的5层偏心结构进行双向地震动作用下的动力反应分析。结果表明,"双功能"软钢阻尼器不但减小了结构的水平位移反应,同时对于多维地震作用下的扭转变形也有较为明显的减震效果。     

考虑参数随机性的高层建筑风振舒适度的非线性黏滞阻尼器优化布设

以顶层加速度作为概率特征量,建立目标函数,分别采用基于随机等效线性化系统的频域方法和基于概率密度演化理论的非线性系统时域方法,进行了考虑结构参数随机性的高层建筑风振舒适度控制的黏滞阻尼器优化布设研究。结果表明：在总黏滞阻尼器系数相同的条件下,以顶层加速度标准差和失效概率为目标函数的黏滞阻尼器优化布设方案,在确定性激励作用下均能显著降低结构的风振响应,且相对于未优化的阻尼器均匀满布方案更经济、更有效。以加速度标准差为目标函数的传统阻尼器优化布设本质上是确定性分析方法,对结构可靠度的提高作用有限,而以加速度失效概率为目标函数的阻尼器优化布设,以结构响应的概率密度函数为优化对象,能显著地提高结构的可靠度,有利于改善高层建筑结构的风振舒适度性能。     

巨型框架减振结构脉动风振的线性最优半主动控制

本文根据线性最优主动控制的原则,提出了同时控制位移、速度和加速度的最优主动控制策略,导出了修正Riccati方程。由此利用磁流体阻尼器,对巨型框架多功能减振结构的脉动风振反应进行了半主动控制,表明该结构体系的半主动控制比被动控制能更显著地减小主、次框架的振动加速度,能更有效地降低主框架的振动位移。     

结构被动和主动多重调谐质量阻尼器控制策略的发展

广泛评述了被动多重调谐质量阻尼器(MTMD)的研究现状，提出了结构主动多重调谐质量阻尼器(AMTMD)和多重主被动调谐质量阻尼器(MAPTMD)的新控制策略，介绍了从AMTMD和MAPTMD的研究进展，并指出了进一步研究的发展方向。     

多层和高层建筑结构减震控制策略

2008年汶川大地震后,地震灾害呈现增多趋势,这对建筑行业影响巨大.本文针对多层和高层建筑结构减震控制进行详细分析,并提出相应的解决对策,以充分保障建筑质量,为今后的减震控制体系提供参考意见.     

巨型框架多功能减振结构脉动风振反应的线性最优半主动控制

根据线性最优主动控制的原则,提出了同时控制位移、速度和加速度的最优主动控制策略,导出了修正Riccati方程。由此利用磁流体阻尼器,对巨型框架多功能减振结构的脉动风振反应进行了半主动控制,表明该结构体系的半主动控制比被动控制能更显著地减小主、次框架的振动加速度,能更有效地降低主框架的振动位移。     

结构双重调谐质量阻尼器(DTMD)控制策略研究

MTMD比TMD具有明显高的鲁棒性。然而,MTMD中各质量块位移不同,总的来说,呈递增或递减趋势,因而各质量块的有效性未得以充分发挥。再者,MTMD比TMD复杂,因而其造价比TMD高。鉴于此,本文提出一种新控制策略——双重调谐质量阻尼器(DTMD)。基于定义的二类最优化目标函数,评价了双重调谐质量阻尼器(DTMD)的控制性能。数值结果表明,利用第二类设计准则(新准则)设计的双重调谐质量阻尼器(DTMD)与由5个TMD组成的MTMD具有近似相同的有效性和鲁棒性。因此,双重调谐质量阻尼器是一种先进的控制策略。     

巨型框架多功能减振结构脉动风振反应的瞬时最优半主动控制

根据瞬时最优主动控制的原则,提出了同时控制位移、速度和加速度的最优主动控制策略,并利用磁流体阻尼器,对巨型框架多功能减振结构的脉动风振反应进行了半主动控制,表明磁流体阻尼器控制结构的半主动控制能显著减小主次框架的振动加速度,能有效地降低主框架的振动位移,其控制效果优于被动控制。     

Optimal control of structures with convex and nonconvex energy densities and variational and hemivariational inequalities

The paper deals with the identification and optimal control problems of structures involving more than one ‘phase’, as for example contact and noncontact zones, or elastic and plastic regions, which are not known a priori. The behaviour of these structures is described by convex or nonconvex energy functions. After a compact formulation of the problems as variational inequalities (the convex case), or as hemivariational inequalities (the nonconvex case), the optimal control problem is formulated and certain propositions are proved. These propositions are then applied to the optimal control and identification problems in elastoplasticity and contact problems.     

A comparative study on optimization of constrained layer damping treatment for structural vibration control

This paper presents a comparison of optimization algorithms for constrained layer damping (CLD) patches’ layout with an objective to minimize the maximum vibration response of the odd modes, which constitutes the dominant acoustic radiation, of a simply supported beam excited by a harmonic transverse force. An analytical model developed for relating the displacement response of the beam with bonded CLD patches and their layout is adopted to formulate the optimization problem. Four different nonlinear optimization methods/algorithms, sub-problem approximation method, the first-order method, sequential quadratic programming (SQP) and genetic algorithm (GA), are then, respectively, used to optimize the CLD patches’ locations and lengths with the aim of minimum displacement amplitude at the middle beam. The efficiency of each considered optimization method is evaluated and also compared in terms of obtained optimal beam displacement and the added weight owing to damping treatment. The results show that GA is most efficient in obtaining the best optimum for this optimization problem in spite of highest computation efforts required to improve its stability.     

结构振动变阻尼滑模控制位置优化

基于灵敏度分析与结构动力学修改的控制策略,以获得结构受控振型最大阻尼比为目标,给出了变阻尼滑模控制器在结构振动控制中的位置优化算法。算例分析表明,优化后的变阻尼结构的滑移模态控制效果接近主动控制效果,但所需能源显著下降,大大提高了其适用性。     

约束阻尼层在钢桁架振动控制中的应用

讨论了应用约束阻尼层在钢桁架结构中的减振问题,首先给出了粘弹性阻尼材料的基本力学特性和约束阻尼层的两种有限元建模方法,通过ANSYS对一约束阻尼结构采用两种不同的有限元模型进行数值仿真分析比较,给出了在ANSYS中准确模拟这类结构的途径,应用这一建模方法对一钢桁架塔柱安装约束阻尼层减振方案的减振效果进行了数值仿真,计算结果表明,安装约束层后结构前两阶弯曲模态阻尼比有较大提高,但扭转模态的模态阻尼比提高很少,约束阻尼层对钢桁架结构弯曲振动控制效果良好。     

Feedback-feedforward control of structures under seismic excitation

While the base acceleration resulting from a seismic activity on a civil engineering structure is not known a priori, it can be measured in real time. In this paper, it is shown that this extra information can be used for achieving a better control of the structure with little additional effort. The approach taken is to augment the equations of motion for the structural system with an appropriate model of the earthquake excitation based on filtering a Gaussian white noise process. The augmented equations of motion are used to determine a control which utilizes both feedback and feedforward compensation. The feedback loop incorporates measurements of the response of the structure into the control law. The information from both the structure and the earthquake excitation model is utilized in the feedforward control law with an observer designed to estimate the states of the eartquake model based upon the base acceleration measurements. A quadratic performance index is used as a measure of optimality of the control algorithms. Results are given which indicate that the proposed method offers advantages in performance over the control method employing only state feedback and that it is also able to improve upon results of the recently develped instntaneous control algorithms. It is also shown that the nostationarity in the earthquake excitation can often be neglected in practical design of linear systems. Finally, a discussion is given of how the method might be coupled with equivalent linearization techniques and extended for use with nonlinear structures.     

Robust control of plate vibration via active constrained layer damping

In this paper, the theoretical modeling of a plate partially treated with active constrained layer damping (ACLD) treatments and its vibration control in an H_∞ approach is discussed. Vibration of the flat plate is controlled with patches of ACLD treatments, each consisting of a viscoelastic damping layer which is sandwiched between the piezo-electric constrained layer and the host plate. The piezo-electric constrained layer acts as an actuator to actively control the shear deformation of the viscoelastic damping layer according to the vibration response of the plate excited by external disturbances. In the first part of this paper, the Mindlin–Reissner plate theory is adopted to express the shear deformation characteristics of the viscoelastic damping layer, meanwhile GHM (Golla–Hughes–McTavish) model of viscoelastic damping material and FEM (finite element model) are incorporated to describe the dynamics of the plate partially treated with ACLD treatment. In the second part, particular emphasis is placed on the vibration control of the first four modes of the treated plate using H_∞ robust control method. For this purpose, an H_∞ robust controller is designed to accommodate uncertainties of the ACLD parameters, particularly those of the viscoelastic damping core which arise from the variation of the operation temperature and frequency. Disturbances and measurement noise are rejected in the closed loop by H_∞ robust controller. In the experimental validation, external disturbances of different types are employed to excite the treated plate. The results of the experimental clearly demonstrate that the proposed modeling method is correct and the ACLD treatments are very effective in fast damping out the structural vibration as compared to the conventional passive constrained layer damping (PCLD).     

Optimal control of a single-basin tidal power scheme in various operating modes

Operation of a tidal power scheme in ebb generation and double generation modes with or without pumping is described. Dynamic programming is used to formulate the control of the scheme to maximize its energy output when operated in any of these modes: in the formulation hydrodynamic effects within the scheme are neglected but real turbine characteristics are used. Optimal control was found to be unnecessary for ebb generation, but it is essential if the scheme is to be operated in any other mode.     

建筑结构被动减震控制的研究与应用

针对建筑结构被动减震控制中的隔震、消能减震及调谐减震技术，介绍了其原理、形式、研究的进展，并从不同的角度分析了被动减震技术的工程应用现状以及被动减震装置的研究应用，最后对被动减震技术研究应用中的一些问题作了探讨。     

土木工程结构振动控制的最佳多重调谐质量阻尼器模型

刚度和阻尼系数保持常量但质量不同的频率线性分布的FD-MTMD能够提供更好的有效性和鲁棒性且最易制作。但是，FD-MTMD存在近零最优平均阻尼比。鉴此，本文提出了刚度和阻尼系数保持常量但质量线性分布的MD-MTMD新模型策略。数值结果表明，MD-MTMD不存在近零最优平均阻尼比，MD-MTMD和FD-MTMD能够近似地达到相同的鲁棒性和有效性。而且，总的来说，MD-MTMD的冲程小于FD-MTMD的冲程。因此。MD-MTMD是土木工程结构振动控制的最佳MTMD模型策略。