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1.
多自由度主动变刚度控制体系的振型控制 总被引：7，自引：1，他引：6
本文利用振型变换技术,将设置了ｍ个控制器的ｂ自由度主动变刚度控制体系降阶为１个自由度的主动变刚度控制体系,进而提出了振型控制律－包括第一振型控制律和主振型控制律,仿真分析结果表明,第一振型控制律可以有效地控制受控结构的相对位移反应,主振型控制律则可以有效地控制受控结构的相对位移反应和层间位移反应。 相似文献
2.
基于能量方程的建筑结构半主动控制 总被引：4，自引：2，他引：2
基于地震作用下结构的能量响应方程,本文提出根据结构吸收能量、相对动能和变形能的变化(对时间的一次导数)进行结构的“开-关”半主动减震的控制律;在物理坐标系中对这3种控制律的动力特征和控制效果,以及作动器参数的选取进行了分析。本文针对建筑结构进行了数值仿真。计算结果表明,本文提出的控制律可以有效地减小了结构的位移响应,对随机不确定的地震波均具有良好的减震效果,适应性强,而且控制器参数合理。其中根据结构变形能推导的控制律的半主动控制效果优于其它2种控制律。 相似文献
3.
设计出一种新型主动变刚度阻尼装置,该装置可向受控结构提供两种等效刚度,使受控结构能主动地避开地震动卓越频率而永远处于非共振的状态。基于变结构控制理论的滑动模态控制算法,推导了该新型阻尼器的两种开关控制律。仿真分析结果表明,这种新型主动变刚度阻尼器的减震效果是非常明显的,可取得明显优于被动控制的减震效果。两种控制律中,连续型滑动模态控制律可以更充分地发挥该新型阻尼器的性能,取得更好的控制效果。 相似文献
4.
介绍了一种具有自主知识产权的新型开关控制型半主动控制系统——主动变刚度.阻尼(AVS.D)系统的减振控制机理,建立了AVS.D结构振动控制体系的运动方程。为了合理补偿AVS.D系统实时控制过程中不可避免地存在着的控制时滞,本文提出一种预测最优控制算法,推导了其开关控制律。为了检验AVS.D系统的减震控制效果及预测最优控制算法的有效性,我们设计研制出AVS.D装置,编制了AVS.D系统预测最优控制的实时控制软件,在某单层钢框架模型上进行了AVS.D系统的模拟地震振动台试验,比较了不同控制方式时的减震效果。研究结果表明,本文所提出的预测最优控制算法是非常有效的,可推广应用于所有开关控制型半主动控制系统。AVS.D系统具有反应放大功能,经济可靠、安全有效,可望有较好的工程应用前景。 相似文献
5.
本文研究半主动控制系统中磁流变(MR)阻尼器的控制力优化问题,从而提高MR阻尼器的半主动控制效果。文中首先建立了多自由度结构MR阻尼器控制系统的运动方程;然后根据MR阻尼器的出力特性提出了结构控制的半主动控制律,并对控制率中MR阻尼器的最大控制力设计值提出了不同的优化取值方法;最后仿真分析了MR阻尼器的不同最大控制力设计值对不同自由度结构的控制效果。研究表明,当设计值取最优控制力的平均绝对值或均方根值时,MR阻尼器的最大控制力比最优控制力的最大值降低了85%,而控制效果降低不多,可以满足对结构的控制要求;降低最大控制力设计值后,不但可以充分发挥MR阻尼器的出力性能,而且可以缩小MR阻尼器的设计尺寸,便于工程应用。 相似文献
6.
地震作用下结构振型组合自校正控制 总被引：1，自引：1，他引：1
本文提出了结构振型组合的自校正控制方法,这使文献〔1〕提出的自校正控制方法可以应用于实际工程结构控制中,为结构的抗震控制提供了简便可行的控制律计算方法。 相似文献
7.
带加强层高层、超高层建筑结构目益增多,针对此类结构提出合理的抗震设计方法十分必要.根据模态理论考虑高阶振型对结构反应的贡献,基于较成熟的多层结构直接基于位移的抗震设计理论,提出了带加强层高层建筑结构直接基于位移的抗震设计方法.方法根据模态理论将结构各个振型分别等效为单自由度体系,计算各单自由度体系的地震响应,进而以振型... 相似文献
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主动变刚度／阻尼控制算法研究 总被引：10，自引：2，他引：8
建立了主动变刚度／阻尼控制系统的理论模型;基于瞬时最优控制算法推导了ＡＶＳＤ系统的开关控制律,并从控制结构的层间位移出发提出了一种直接根据结构动力反应符号确定的开关控制律。 相似文献
10.
提出了应用磁流变阻尼装置的多自由度结构顶层隔振控制方法.首先,以大质量比TMD控制的减振机理为基础,对顶层隔振结构的动力特性进行研究,建立合理的顶层隔振结构体系;然后,采用磁流变阻尼器对顶层隔振结构的隔振层进行被动和半主动控制,以避免其控制范围较窄的缺点;最后,对三自由度结构进行顶层隔振控制时程分析,得到了比较理想的控制效果. 相似文献
11.
Theory and implementation of switch‐based hybrid simulation technology for earthquake engineering applications 
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下载免费PDF全文 Hybrid simulation (HS) is a novel technique to combine analytical and experimental sub‐assemblies to examine the dynamic responses of a structure during an earthquake shaking. Traditionally, HS uses displacement‐based control where the finite element program calculates trial displacements and applies them to both the analytical and experimental sub‐assemblies. Displacement‐based HS (DHS) has been proven to work well for most structural sub‐assemblies. However, for specimens with high stiffness, traditional DHS does not work because it is difficult to precisely control hydraulic actuators in small displacement. A small control error in displacement will result in large force response fluctuations for stiff specimens. This paper resolves this challenge by proposing a force‐based HS (FHS) algorithm that directly calculates trial forces instead of trial displacements. The proposed FHS is finite element based and applicable to both linear and nonlinear systems. For specimens with drastic changes in stiffness, such as yielding, a switch‐based HS (SHS) algorithm is proposed. A stiffness‐based switching criterion between the DHS and FHS algorithms is presented in this paper. All the developed algorithms are applied to a simple one‐story one‐bay concentrically braced moment frame. The result shows that SHS outperforms DHS and FHS. SHS is then utilized to validate the seismic performance of an innovative earthquake resilient fused structure. The result shows that SHS works in switching between the DHS and FHS modes for a highly nonlinear and highly indeterminate structural system. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
12.
地震下结构振动的最优控制算法模型比较与改进 总被引：8，自引：0，他引：8
模拟地震激励输入结构的过程，将控制目标函数化解到每个时间步长上。用激励所产生的脉冲响应重新构造控制目标函数，直接从泛函变分出发，推导出了一种改进的最优控制算法，并用状态转移的数值方法加以实现。从概念上讲，本算法是一种更为合理的结构最优控制算法。算例表明，在相同控制能量下，本算法能更有效地削减响应峰值，且稳定性良好。 相似文献
13.
The integrated optimum problem of structures subjected to strong earthquakes and wind excitations, optimizing the number of actuators, the configuration of actuators and the control algorithms simultaneously, is studied. Two control algorithms, optimal control and acceleration feedback control, are used as the control algorithms. A multi‐level optimization model is proposed with respect to the solution procedure of the optimum problem. The characteristics of the model are analysed, and the formulation of each suboptimization problem at each level is presented. To solve the multi‐level optimization problem, a multi‐level genetic algorithm (MLGA) is proposed. The proposed model and MLGA are used to solve two multi‐level optimization problems in which the optimization of the number of actuators, the positions of actuators and the control algorithm are considered in different levels. In problem 1, an example structure is excited by strong wind, and in problem 2, an example structure is subjected to strong earthquake excitation. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
14.
Based on the genetic algorithms (GAs), a fuzzy sliding mode control (FSMC) method for the building structure is designed in this research. When a fuzzy logic control method is used for a structural system, it is hard to get proper control rules directly, and to guarantee the stability and robustness of the fuzzy control system. Generally, the fuzzy controller combined with sliding mode control is applied, but there is still no criterion to reach an optimal design of the FSMC. In this paper, therefore, we design a fuzzy sliding mode controller for the building structure control system as an optimization problem and apply the optimal searching algorithms and GAs to find the optimal rules and membership functions of the FSMC. The proposed approach has the merit to determine the optimal structure and the inference rules of fuzzy sliding mode controller simultaneously. It is found that the building structure under the proposed control method could sustain in safety and stability when the system is subjected to external disturbances. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
15.
This paper presents a family of semi‐active control algorithms termed as active interaction control (AIC) used for seismic response control of civil structures. AIC control algorithms include active interface damping (AID), optimal connection strategy (OCS) and tuned interaction damping (TID). A typical SDOF AIC system consists of a primary structure, an auxiliary structure and an interaction element. The auxiliary structure typically has stiffness comparable to that of the primary structure while its natural frequency is much higher than that of the primary structure. Interactions between the primary and the auxiliary structures are defined by specific AIC control logic such that vibrational energy is extracted from the primary structure into the auxiliary structure during a locking phase and dissipated in the auxiliary structure in the subsequent unlocking phase. The stability of AIC control algorithms is shown using the Lyapunov direct method. The efficacy of AIC control algorithms is demonstrated by the results of numerical simulations of SDOF systems subjected to seismic ground motions. Practical issues such as sampling period and time delay are also investigated in this study. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
16.
Semi‐active stiffness damper (SASD) is one of many semi‐active control systems with the capability to mitigate the dynamic response using only a small amount of external power. The system consists of a hydraulic damper connected to the bracing frame in a selected story unit. In this paper, study of a SASD in two building models of five‐stories under four benchmark earthquake records is reported. The purpose of this study is to evaluate the effectiveness of the control system against structure type and varying earthquake inputs. Various control laws are chosen to work with SASD, such as: resetting control, switching control, linear quadratic regulator (LQR) and modified LQR, and the results are compared with no control and passive control cases. Numerical results show that the use of a SASD is effective in reducing seismic responses. Control effectiveness is dependent on the type of structure and earthquake excitation. Passive control is less effective than other control cases as expected. Resetting control, switching control and LQR generally perform similarly in response reduction. While modified LQR is more efficient and robust compared with other control algorithms. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
17.
A control method is presented for reducing the dynamic response of structures in the inelastic material range using a control force from an active bracing system. Recent full-scale experiments have verified the feasibility of implementing active control systems for control of seismic structures with existing technology. The proposed method of continuous pulse control uses closed-loop feedback control as a combination of two algorithms. The first is the instantaneous optimal algorithm which was derived assuming linear material behaviour, and the second is pulse control which applies a corrective pulse when a prespecified structural displacement, velocity, or acceleration threshold is exceeded. The three criteria of displacement, velocity, and acceleration lead to three pulse control schemes. Each of the three schemes is used in conjunction with the instantaneous optimal control to yield three continuous pulse algorithms, the displacement continuous pulse, velocity continuous pulse and acceleration continuous pulse. Comparisons between the three continuous pulse algorithms and the pulse control for seismic structures in the inelastic range show that the continuous pulse algorithms use less control energy and reduce the response better than pulse control. A comparison between the velocity continuous pulse and the non-linear optimal algorithm shows that the velocity continuous pulse uses a larger control force but is more adaptable than the non-linear optimal algorithm, in the sense that it can reduce the response of a given structure to various probable earthquakes. The non-linear optimal algorithm is more effective than the velocity continuous pulse for a single specific earthquake but is not as effective for other earthquakes which may occur in the life of the structure. 相似文献
18.
This paper proposes an online test technique that employs mixed control of displacement and force. Two types of mixed control, ‘displacement–force combined control’ and ‘displacement–force switching control’ are proposed. In displacement–force combined control, one jack is operated by displacement‐control, and another is operated by force‐control. Validity of the combined control technique is demonstrated by a series of online tests applied to a base‐isolated structure subjected to horizontal and vertical ground motions simultaneously. The substructuring technique is employed in the tests, and the base‐isolation layer is tested, with the rest of the structure modeled in the computer. Displacement‐control and force‐control were adopted for simulating the horizontal and vertical response, respectively. Both displacement‐ and force‐control were implemented successfully despite interference between the two jacks. Earthquake responses of the base‐isolated structure involving the effects of varying axial forces on the horizontal hysteretic behavior of the base‐isolation layer were simulated. In the displacement–force switching control, the jack was operated by displacement‐control when the test specimen was flexible but switched to force‐control once the specimen became stiff. Validity of the switching control technique was also checked by a series of online tests applied to the base‐isolated structure subjected to vertical ground motions. Switching between displacement‐control and force‐control was achieved when the axial force applied to the base‐isolation layer changed from tension to compression or from compression to tension. Both the displacement‐ and force‐control were successful even with many rounds of switching. The test revealed that large accelerations occurred on the floor immediately above the base‐isolation layer at the instants when the axial force of the base‐isolation layer changed from tension to compression. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
19.
In this paper, a semi-active control by MR-damper is researched; its purpose is to effectively control vibration of asymmetrical cable-stayed bridges when earthquake is loaded on the type of bridge. For an experimental study, a model of 10.2 m high and 28 m long asymmetrical cable-stayed bridge structure was built being similar to a real one in size and function. A MR damper was also designed in proper size suitable for the control of the model. The experiment was performed in the way in which three piers were fixed on three shaking tables with 30% of El-centro earthquake wave, and a control device was placed on the lower part of its upper deck for horizontal control. As for control algorithms, Lyapunov and Clipped-optimal control algorithms were applied. The effectiveness of the semi-active control with MR damper for the asymmetrical cable-stayed bridge was measured under five control conditions: Un-control, Passive-off, Passive-on, Lyapunov Control, Clipped-optimal Control. The experiment showed that the semi-active control applying Lyapunov and Clipped-optimal algorithms effectively increased controllability almost in double, and decreased displacement 75% compared with the condition of passive-off. Therefore the semi-active method suggested in this paper is proven effective in controlling asymmetrical cable-stayed bridges. 相似文献
20.
Base isolated structures have been found to be at risk in near-fault regions as a result of long period pulses that may exist in near-source ground motions.Various control strategies,including passive,active and semi-active control systems,have been investigated to overcome this problem.This study focuses on the development of a semi-active control algorithm based on several performance levels anticipated from an isolated building during different levels of ground shaking corresponding to various earthquake hazard levels.The proposed performance-based algorithm is based on a modified version of the well-known semi-active skyhook control algorithm.The proposed control algorithm changes the control gain depending on the level of shaking imposed on the structure.The proposed control system has been evaluated using a series of analyses performed on a base isolated benchmark building subjected to seven pairs of scaled ground motion records.Simulation results show that the newly proposed algorithm is effective in improving the structural and nonstructural performance of the building for selected earthquakes. 相似文献