共查询到19条相似文献，搜索用时 343 毫秒
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林剑 《地震工程与工程振动》2015,(2):181-186
研究采用阻尼器对连体高层结构的地震响应进行振动控制。首先从结构动力方程出发,推导了在主塔与连廊之间设置有黏滞阻尼器的有控结构的基本振动控制方程;进而通过数值模拟,以某实际工程为原型,尝试将连廊与主塔间的斜撑利用黏滞阻尼器进行替换,分别在不同地震激励下比较了有控结构和无控结构的地震响应。分析结果表明,采用黏滞阻尼器可以有效降低结构的层剪力、结构位移、加速度等地震响应;同时能量分析的结果也表明本文采用的减振方案在不同地震激励下都可以有效耗散地震能量,由此得出结论采用黏滞阻尼器提高连体高层结构的抗震安全性是可行的。 相似文献
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阻尼器是一种效果良好的减震装置,将阻尼器安装于结构中能够适时为结构体系提供阻尼力,从而减小地震作用对结构的破坏。黏滞阻尼器对振动的反应比较敏感,在结构受到较小振动时就可以发挥其减震效果,其阻尼力会随着振动周期和使用状态温度的不同而变化。当地震发生时,安装在结构中的阻尼器会消减地震作用,降低传导到主结构体系的地震能量,减小结构相对位移。本文介绍了黏滞阻尼器的工作原理和安装有黏滞阻尼器的结构体系的阻尼比的计算方法,对减震结构的减震效果的评析方法做出探讨,并以一安装有黏滞阻尼器的台湾某既有钢框架结构为例,分析了(1)该结构在遭受地震作用时的地震反应;(2)该结构体系在不同地震作用水平时的阻尼比,包括主体结构阻尼比和黏滞阻尼器阻尼比;(3)结构安装黏滞阻尼器后的减震效果。实例对本文的减震评析方法和减震效果进行了说明和分析,计算及分析结果表明利用黏滞阻尼器加固既有结构能够取得较好的减震效果,本文所提减震效果评析方法是一种实用有效的评析方法,对类似工程的减震评析具有一定的参考价值。 相似文献
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《地震工程与工程振动》2017,(5)
巨子有控结构体系(MSCSS)是一种具有自控能力的新型结构体系。本研究将磁流变(MR)阻尼器与MSCSS的工作机理相结合,采用模糊神经网络建立MR阻尼器的控制规则,利用遗传算法对模糊神经网络结构进行优化,在考虑构件发生非线性变形的情况下,研究了不同场地地震作用时的MSCSS非线性振动响应控制效果。通过与被动控制工况和以LQR算法为基础的半主动控制工况进行时域、频域范围内的对比研究,结果表明本文设计的模糊神经网络算法可以有效减小MSCSS的地震响应,并且在结构构件进入非线性状态以后仍然保持良好的稳定性,大大提高了结构的抗震性能。 相似文献
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某周期比超限偏心结构地震反应控制分析 总被引：1，自引：0，他引：1
本文以周期比超限的某偏心结构工程为研究背景,基于SAP2000建立三维有限元模型,采用黏滞阻尼器、黏弹性阻尼器、软钢阻尼器、复合铅黏弹性阻尼器和钢支撑五种减震方案对其进行扭转控制,针对不同扭转控制方案分别进行了模态分析、反应谱分析和动力时程分析,对比研究了多遇地震作用下各控制方案的周期比、层间位移、支撑内力及阻尼器的耗能能力。研究表明:五种控制方案均具有有效抑制结构扭转振动响应的能力,降低结构的最大层间位移角,并使之满足规范要求;后四种控制方案能明显减小结构的周期比,将结构第一扭转反应控制在第三振型;对于此类偏心结构体系的扭转振动控制,本文建议阻尼器设置应尽量远离刚度中心,以达到最佳扭转控制效果。 相似文献
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黏滞阻尼器作为一种有效的消能减震装置,已在钢结构建筑中得到了大量应用.然而由于钢结构的延性和阻尼特征,实用的钢结构附加黏滞阻尼器设计方法仍需深度探讨.文中提出一种基于黏滞阻尼器延性需求的减震设计方法.首先,根据钢结构需求量化层间位移角性能目标及目标附加阻尼比,计算黏滞阻尼器延性需求,并确定黏滞阻尼器布置数量、进行控制效... 相似文献
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为改善近断层地震动作用下隔震桥梁结构的抗震性能,基于Benchmark结构振动控制问题,研究附加黏滞阻尼器、磁流变(MR)阻尼器的组合隔震策略.非线性动力分析过程中,优化了黏滞阻尼器的阻尼系数和速度指数,并设计了分散模糊控制器来确定施加给磁流变阻尼器的电压.研究结果表明:采用黏滞阻尼器和磁流变阻尼器可提高隔震桥梁结构在... 相似文献
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向量式有限元是以向量力学为基础的一种新的结构分析方法,在处理结构大变形等复杂行为时具有较大的优势。基于向量式有限元理论建立了黏滞阻尼单元,对附加黏滞阻尼器的平面钢框架结构进行了抗竖向连续倒塌动力分析,结合拆除构件法,采用MATLAB编制可以考虑初始变形的瞬时卸载法程序,实现结构在构件拆除前的静力分析和构件拆除后动力分析的全过程统一。研究了阻尼器布置位置和参数在结构抗竖向连续倒塌中的性能需求,以失效点竖向位移时程曲线、梁端转角、动力放大系数和结构塑性铰分布为参考指标,对比分析布置阻尼器前后钢框架结构的抗连续倒塌能力。结果表明向量式有限元是一种研究结构竖向连续倒塌动力响应的有效方法,合理布置阻尼器能够有效控制剩余结构的变形和振动,降低构件内力,减少塑性铰个数,较大地提高结构的抗竖向连续倒塌能力。 相似文献
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黏滞阻尼器在单层网壳结构中的优化布置 总被引：1，自引：0，他引：1
目前采用黏滞阻尼器对单层网壳结构进行减振控制时,阻尼器最优布置位置通过试算确定。针对此问题,推导了地震作用下黏滞阻尼器耗能公式,提出了以能量比例系数为评价指标的阻尼器优化布置准则。以单层球面网壳和单层柱面网壳为例,对比分析了地震作用下分别采用优化布置准则与现有布置方式布置阻尼器时结构最大节点位移减振系数,验证了所提出优化布置准则的正确性及在单层球面网壳和单层柱面网壳中的适用性。 相似文献
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A two‐step direct method for estimating the seismic response of nonlinear structures equipped with nonlinear viscous dampers 
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下载免费PDF全文 The insertion of fluid viscous dampers in building structures is an innovative technology that can improve significantly the seismic response. These devices could be very useful also in the retrofit of existing buildings. The effect of this typology of damping system is usually identified with an equivalent supplemental damping ratio, which depends on the maximum displacement of the structure, so that iterative procedures are required. In this paper, a simplified direct assessment method for nonlinear structures equipped with nonlinear fluid viscous dampers is proposed. The method proposed in this study is composed by two steps. The first one yields the direct estimate of the supplemental damping ratio provided by nonlinear viscous dampers in presence of a linear elastic structural response. The second step extends the procedure to structures with nonlinear behavior. Both graphical and analytical approaches have been developed. The proposed method has then been verified through several applications and comparisons with nonlinear dynamic analyses. Moreover, an investigation has been performed with regard to the influence of the relations that define the damping reduction factor and the hysteretic damping. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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一种新型粘滞阻尼材料的试验研究 总被引：5，自引：0，他引：5
粘滞阻尼材料是粘滞阻尼器的重要组成部分,其性能直接影响阻尼器的各项性能指标。本文研制了一种新型的粘滞阻尼材料,并通过各项试验对其高温下的热稳定性、化学安定性、耐久性、安全性及动态力学性能进行了深入研究。试验表明,本文研制的粘滞阻尼材料具有安全、稳定、耐久性好、耗能能力强等特点,可满足结构耗能构件的要求。 相似文献
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Active multiple tuned mass dampers (AMTMD) consisting of many active tuned mass dampers (ATMDs) with a uniform distribution of natural frequencies have been, for the first time, proposed for attenuating undesirable vibrations of a structure under the ground acceleration.The multiple tuned mass dampers (MTMD) in the AMTMD is manufactured by keeping the stiffness and damping constant and varying the mass. The control forces in the AMTMD are generated through keeping the identical displacement and velocity feedback gain and varying the acceleration feedback gain. The structure is represented by its mode‐generalized system in the specific vibration mode being controlled using the mode reduced‐order method. The optimum parameters of the AMTMD are investigated to delineate the influence of the important parameters on the effectiveness and robustness of the AMTMD by conducting a numerical searching technique. The parameters include the frequency spacing, average damping ratio, tuning frequency ratio, total number and normalized acceleration feedback gain coefficient. The criterion, which can be stated as the minimization of the minimum values of the maximum dynamic magnification factors (i.e. Min.Min.Max.DMF), is chosen for the optimum searching. Additionally, for the sake of comparison, the results of the optimum MTMD (the passive counterpart of AMTMD) and ATMD are also taken into account in the present paper. It is demonstrated that the proposed AMTMD can be expected to significantly reduce the oscillations of structures under the ground acceleration. It is also shown that the AMTMD can remarkably improve the performance of the MTMD and has higher effectiveness than ATMD. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
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针对现有附加有效阻尼比计算方法存在的问题,本文从能量的角度揭示了阻尼比对结构影响的机理.从结构设计的角度,提出一种在时程分析下基于楼层剪力的消能减震结构等效阻尼比计算方法.对布置黏滞阻尼器和软钢阻尼器的消能减震模型,采用本文提出的等效阻尼比计算方法,建立等效结构进行结构响应对比.结果表明,由该计算方法得到的等效阻尼比能... 相似文献
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This paper deals with steel moment frames combined with hysteretic dampers. Specifically, it examines the strength of dampers required to minimize damage to moment frames under earthquake loading. The important structural variables are the ratio of the dampers' shear strength to the maximum resistance, termed β in this study, and the relative stiffness between the damper and the main frame, termed k. The equivalent viscous damping ratio of the entire structural system is affected by the quantities β and k and the ductility ratio of the main frame. The optimum dampers' strength ratio (βopt), which maximizes the equivalent viscous damping ratio, was formulated as a function of k, and it was found that βopt is independent of the ductility ratio of the main frame. Earthquake response analysis confirmed that damage to the main frame can be significantly reduced by hysteretic dampers and minimized at the value of βopt. © 1998 John Wiley & Sons, Ltd. 相似文献
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Choice between series and parallel connections of hysteretic system and viscous damper for seismic protection of structures 下载免费PDF全文
下载免费PDF全文 Supplemental viscous damping devices are generally envisioned to be connected in parallel to the inelastic parent structure or hysteretic damping devices. This gives rise to higher base shear, and often greater ductility demand of the hysteretic system. The series connection of the viscous and hysteretic system (the inelastic structure or a damper) is an alternative approach. In this paper, comparisons between the series and parallel connections of the hysteretic system and viscous dampers are done through response spectra analyses of single degree of freedom structures. Ductility demand of the hysteretic system and the total base shear are chosen as the response quantities. For the series model, a semi‐implicit solution scheme for classical Maxwell model is modified to include the inelasticity of the time‐independent hysteretic spring. It is observed that the series connection of the 2 dampers gives lower base shear than does the parallel connection. For long‐period and low‐damping structures, the ductility demand of the hysteretic system in series connection is higher than that in parallel connection. Increasing the viscous damping in series connection reduces the ductility demand substantially, lower than that obtained in parallel connection. Practical methods for implementing the series and parallel connections, in line with roof isolation, are also suggested. 相似文献
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The newly proposed mega sub-controlled structure system(MSCSS) and related studies have drawn the attention of civil engineers for practice in improving the performance and enhancing the structural effectiveness of mega frame structures. However, there is still a need for improvement to its basic structural arrangement. In this project, an advanced, reasonable arrangement of mega sub-controlled structure models, composed of three mega stories with different numbers and arrangements of substructures, are designed to investigate the control performance of the models and obtain the optimal model configuration(model with minimum acceleration and displacement responses) under strong earthquake excitation. In addition, the dynamic parameters that affect the performance effectiveness of the optimal model of MSCSS are studied and discussed. The area of the relative stiffness ratio RD, with different mass ratio MR, within which the acceleration and displacement of the optimal model of MSCSS reaches its optimum(minimum) value is considered as an optimum region. It serves as a useful tool in practical engineering design. The study demonstrates that the proposed MSCSS configuration can efficiently control the displacement and acceleration of high rise buildings. In addition, some analytical guidelines are provided for selecting the control parameters of the structure. 相似文献
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Buildings are continually subject to dynamic loads, such as wind load, seismic ground motion, and even the load from internal utility machines. The recent trend of constructing more flexible high‐rise buildings underscores the importance of including viscoelastic dampers in building designs. Viscoelastic dampers are used to control the dynamic response of a building. If the seismic design is based only on the linear response spectrum, considerable error may occur when calculating the seismic response of a building; rubber viscoelastic dampers show non‐linear hysteretic damping that is quite different from viscous damping. This study generated a non‐linear response spectrum using a non‐linear oscillator model to simulate a building with viscoelastic dampers installed. The parameters used in the non‐linear damper model were obtained experimentally from dynamic loading tests. The results show that viscoelastic dampers effectively reduce the seismic displacement response of a structure, but transmit more seismic force to the structure, which essentially increases its seismic acceleration response. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
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Design formulas for supplemental viscous dampers to building structures are readily available in FEMA provisions and MCEER research reports. However, for the design of supplemental viscous dampers corresponding to a desired system damping ratio of highway bridges, there exist, if any, few design guidelines. This is particularly true if the bridge components such as elastomeric bearings, piers and abutment possess different damping ratios, stiffnesses, and lumped masses. In this paper, the design formulas for supplemental viscous dampers to highway bridges have been derived based on the concept of ‘composite damping ratio’. The design formulas can be used to determine the damping coefficients of the dampers corresponding to a desired system damping ratio of the bridge in which different component damping ratios may be assumed for the elastomeric bearings, piers and abutments. The proposed design formulas are numerically validated by comparing the seismic responses of a three‐span bridge equipped with viscous dampers with those of the same bridge without viscous dampers but with an assigned inherent system damping ratio equal to the target system damping ratio. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献