规则波作用下圆形调谐液体阻尼器的试验研究

对规则波作用下圆形调谐液体阻尼器的可行性及有效性进行了试验研究，探索调谐液体阻尼器对于固定式海洋平台结构成振的实用性。调谐液体阻尼器的减振性能通过结构响应的减小程度来评价。试验观测了容器中液体的运动形态，同时考虑容器的大小、数目，阻尼器与平台结构、波浪三者之间的频率比，质量比以及激振波浪参数等诸多因素的影响，得到了利用调谐液体阻尼器进行固定式海洋平台减振设计的具有指导意义的结论。     

Study on the dynamic characteristic of a U-type tuned liquid damper

By means of Lagrange's equation, the “coupled” equations of motion for a horizontal plate carrying a U-type tuned liquid damper (TLD) are derived. The “uncoupled” equations of motion for the liquid (in the TLD) and the structural system are then obtained by decoupling the “coupled” ones. Unlike the existing literature to indirectly determine the natural frequencies of a damped vibrating system by using the resonant method, the “complex” eigenvalues of the coupled damped system are obtained directly from the associated eigenvalue equations. Besides, the pressure intensities in the two air chambers and the sizes of the two vertical tanks together with the horizontal conduit are arbitrary in the formulation of this paper. The influence of some key parameters of the TLD on the dynamic responses of the structural system is studied.     

Energy Anaiysis for TMD-Structure Systems Subjected to Impact Loading

This paper investigates the characteristics of reduction of the lateral vibration by use of a Tuned Mass Damper (TMD) for offshore jacket platforms under impact loading. Unlike traditional analysis, the present analysis focuses on the energy concept of TMD/structure systems. In this study, a time domain is taken. The platform is modeled as a simplified single-degree-of-freedom (SDOF) system by extraction of the first vibration mode of the structure and the excited force is assumed to be impact loading. The energy dissipation and energy transmission of the structure-TMD system are studied. Finally, an optimized TMD design for the modeled platform is demonstrated based on a new type of cost function - maxi-mum dissipated energy by TMD. Results indicate that TMD control is effective in reducing the Standard deviation of the deck motion but less effective in reducing the maximum response under impact loading.     

Dynamic performance of cable-stayed bridge tower with multi-stage pendulum mass damper under wind excitations -- II： Experiment

The possibility of using a multi-stage pendulum mass damper(MSPMD) to control wind-induced vibration of a single column tower of a cable-stayed bridge during construction was studied theoretically in part Ⅰ of this work.In this paper,the performance of the MSPMD for reducing bridge tower vibration is studied experimentally.A MSPMD model and a tower model of the bridge with geometry scaling of 1100 were designed and manufactured.Calibration of the MSPMD model with different wire lengths is conducted to verify the analytical model of the damper.A series of tests for the uncontrolled freestanding tower,tower with cables,and tower with MSPMD model are then performed under harmonic and white noise excitations.The experimental results show that the responses of the tower model significantly decrease with the installation of the MSPMD model,which demonstrates the effectiveness of the MSPMD to mitigate the vibration of the bridge tower.     

Seismic response control of a building complex utilizing passive friction damper: experimental investigation

Multi‐storey main buildings constructed with a low‐rise podium structure possess some architectural merits but the setback features of such a building complex may lead to seismic response enlargement of the main buildings. This paper explores the possibility of using passive friction dampers to connect the podium structure to the main buildings to prevent their seismic response enlargement without violating the architectural features. A series of shaking table tests were carried out on one 3‐storey and one 12‐storey building models in fully‐separated, rigidly connected, and friction damper‐linked configurations. Four sets of seismic ground motions were selected as inputs to the shaking table. The control competence of two buildings linked with friction damper was evaluated by comparison of their responses with those from fully‐separated and rigidly connected cases. Experimental results showed that unfavourable seismic response amplification did occur in the building complex in the rigidly connected case. By contrast, friction damper showed effectiveness in reducing absolute acceleration and interstorey drift responses of both buildings if friction force level was appropriately applied. Copyright © 2005 John Wiley & Sons, Ltd.     

Semi‐active neuro‐control for base‐isolation system using magnetorheological (MR) dampers

Vibration mitigation using smart, reliable and cost‐effective mechanisms that requires small activation power is the primary objective of this paper. A semi‐active controller‐based neural network for base‐isolation structure equipped with a magnetorheological (MR) damper is presented and evaluated. An inverse neural network model (INV‐MR) is constructed to replicate the inverse dynamics of the MR damper. Next, linear quadratic Gaussian (LQG) controller is designed to produce the optimal control force. Thereafter, the LQG controller and the INV‐MR models are linked to control the structure. The coupled LQG and INV‐MR system was used to train a semi‐active neuro‐controller, designated as SA‐NC, which produces the necessary control voltage that actuates the MR damper. To evaluate the proposed method, the SA‐NC is compared to passive lead–rubber bearing isolation systems (LRBs). Results revealed that the SA‐NC was quite effective in seismic response reduction for wide range of motions from moderate to severe seismic events compared to the passive systems. In addition, the semi‐active MR damper enjoys many desirable features, such as its inherent stability, practicality and small power requirements. The effectiveness of the SA‐NC is illustrated and verified using simulated response of a six‐degree‐of‐freedom model of a base‐isolated building excited by several historical earthquake records. Copyright © 2006 John Wiley & Sons, Ltd.     

基于AFSMC算法的结构非线性振动MR控制与仿真分析

作为最近发展起来的高性能半主动控制装置,磁流变阻尼器通过改变磁场强度来调节控制力,可靠度高,体积小,出力大,并且具有Fail-Safe的特点,是一种具有广泛应用前景的新型结构控制装置。本文主要研究结构非线性振动的磁流变阻尼半主动控制。首先采用我们提出的自适应模糊滑模控制(AFSMC)算法得到了结构非线性振动的主动控制力,然后参照主动控制力,提出和仿真实现了结构非线性振动的磁流变阻尼半主动控制。最后,针对3层和20层benchm ark非线性模型,每层均设置一个磁流变阻尼器,对在给定的地震动下的结构响应进行了计算,分析了半主动控制跟踪主动控制的效果,并且对于半主动控制下的结构位移响应、加速度响应等各项指标也进行了对比分析。仿真结果表明,由于自适应模糊滑模控制算法与半主动控制算法相结合可以很好地实现结构非线性振动的半主动控制,所以能够得到令人满意的控制结果。     

Analysis on influence of seismic travelling wave effect on semi-active control for long-span rigid-continuous bridge

Introduction The methods of enhancing ability of bridge to resist earthquake disaster can be divided into two aspects. One is enhancing the resisting earthquake ability from the designing ways; the other is adding control devices on the existing structures to effectively control the seismic responses of bridge from the vibration control ways. The great progress has been made in structure control technique in the last years. It has the advantages of security, validity, economical and wide appli…     

薄弱层设置耗能阻尼器支撑的钢框架模型振动台试验

设计制作了一个五层钢框架模型,在其第一层、第三层和第五层薄弱层分别设置摩擦阻尼器、粘弹性阻尼器和粘弹性-摩擦阻尼器等三种耗能阻尼器支撑,进行了罕遇地震和多遇地震下的振动台试验。试验结果表明,耗能阻尼器支撑能够有效地控制结构的地震反应。     

高拱坝伸缩横缝间布设阻尼器对坝体地震反应影响的研究

对设置伸缩横缝的小湾高拱坝结构，应用子结构理论，分别就正常高水位与常遇低水位两种水位工况，考虑坝体伸缩横缝在地震交变荷载作用下反复开合引起的缝面间滑移、接触等效应的影响，坝体-库水的相互作用而产生的动水压力的影响，对坝体的抗震性能进行了地震反应分析。对伸缩缝间设置阻尼器这新的设计思想进行了可行性的研究，论证推导了阻尼器的计算模型，探讨了阻尼器对坝体抗震性能的影响。