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1.
大跨度悬索桥振动控制的双向TMD参数研究   总被引:1,自引:1,他引:0  
用时域内的逐步积分法对无TMD和带有不同参数TMD的悬索桥进行了时程分析,结果表明,TMD的参数对结构的动力特性的抑振效果均有较大的影响,TMD的频率不仅影响振动控制的效果也影响结构的表观阻尼,扭转振动的控制可由侧向TMD来实现。  相似文献   

2.
用于控制高柔结构振动的POD技术   总被引:5,自引:0,他引:5  
本文通过模型试验和理论分析研究了一种控制高柔结构振动的新方法---POD(摆、油阻尼器)减振系统。文中详细分析了其减震原理,并提出了与试验结果相吻合的三角形非缄性滞回模型。试验结果表明,在接近调谐状态下POD法可减振48%。数据计算的结果也表明,POD不仅减振效果比TMD高得多,而且有效频带也宽得多。POD系统具有造价低、易安装、占用空间小、免维护等优点,可用于风可于震等荷载引起的电视塔、悬索桥塔  相似文献   

3.
多层房屋结构TMD“加层减震”试验研究和应用   总被引:16,自引:3,他引:13  
对某个6层框架进行了有,无TMD结构的振动台对比试验,验证了TMD对多层结构具有一定的减震效果。应用TMD方法对某个7层框架结构进行了“加层减震”改造,分析表明,改造后的建筑与改造前相比,结构的底部剪力下降了约30%。  相似文献   

4.
采用频域分析方法考虑了(TMD)在结构中的位置和结构振型特征,推导了具有单个调谐质量阻尼器(STMD)和多个调谐质量阻尼器(MTMD)的多自由度结构受控振型广义坐标的频率响应方程,同时还相应给出了具有STMD和MTMD的非广义单自由度结构的频率响应方程,通过对比分析得出了重要的结论。  相似文献   

5.
悬索桥主塔作为核心支撑构件,在地震作用下特别是罕遇地震作用下其结构破坏模式就显得尤其重要,也是保证生命线工程结构震后安全的基础,而目前对大跨度悬索桥破坏模式的研究还很不完善。本文借助Open Sees有限元分析程序,以哈尔滨阳明滩大跨度悬索桥的设计方案为背景,以悬索桥的钢筋混凝土桥塔为研究重点,分析三维罕遇地震作用时,桩-土-结构的动力相互作用对大跨度悬索桥桥塔顺桥向破坏模式的影响。文中以在三维地震作用下塔底截面曲率达到等效屈服曲率,从而桥塔产生具有同时性特征的双塑性铰为破坏基准。分析发现在顺桥向罕遇地震作用下,悬索桥塔结构往往在桩基产生塑性屈服后塔底截面再出现塑性;同时发现考虑桩-土-结构相互作用可以延缓塔底截面进入塑性的时间,但会加大塔底截面的地震反应。  相似文献   

6.
设置TMD,TLD控制系统的高层建筑风振分析与设计方法   总被引:15,自引:0,他引:15  
本文结合我国现行风荷载规范,研究设置TMD、TLD控制系统的高层建筑风振分析与抗风设计的实用方法。首先,TMD、TLD系统的风振控制效果归并到了受控结构的内荷载折减上;其次,导出了满足舒适度标准的结构动侧移界限的相应的计算公式;第三,比较了TMD、TLD系统的控制效果以及分别对高层钢和钢筋混凝土结构的控制效果;最后,通过大量的计算和分析,分别确定了TMD、TLD系统参数的最佳取值区间以及参数之间的  相似文献   

7.
大跨度悬索桥在交通荷载和环境激励下,加劲梁产生持续不断的纵向往复运动,这类振动会导致悬索桥上的连接构件如伸缩缝等出现疲劳破坏。抑制这类振动一般是在梁端安装阻尼装置,这类装置不仅能够减少运营状态下的梁端位移,还能减弱地震作用下的梁端位移响应。本文提出采用耐久性能良好的新型电涡流阻尼器(ECD)进行梁端位移控制并对其减振效果进行了评估。首先对某大跨度悬索桥的实测纵向位移数据进行时域和频域分析,通过简化建立了悬索桥纵向振动的单自由度模型(SDOF),并反演了运营状态下的等效外力时程。然后对悬索桥简化SDOF模型在运营状态等效外力时程作用下和地震激励下的响应进行了计算,并评估了ECD在运营低速状态下线性阻尼和地震高速状态下非线性阻尼的减振(震)控制效果,提出了平衡两种状态控制目标的阻尼器参数合理取值范围,为ECD在悬索桥加劲梁纵向位移控制领域的应用提供了一定的理论依据。  相似文献   

8.
根据高耸造粒结构具有旋转壳外形的特点,提出了一种环状半主动可控调频质量阻尼器(TMD)系统,并以旋转壳理论编制了有限元程序,对TMD系统的振动参数进行了计算。结果表明,可控TMD系统具有显著的减震效果,为结构震后修复提供了一种经济,方便,适用,快捷的新途径。  相似文献   

9.
高层建筑地震反应最优多重TLD控制   总被引:3,自引:1,他引:3  
本文以坑层建筑地震反应进行了最优多重TLD(MTLD)s控制研究。文中阐述了TLD系统的工作原理笔MTLDs系统的参数;建立了多层结构-TMLDs系统耦联体系的运动方程;分析了MTLDs系统的参数对在谐波作用下多层结构动力反应的影响以及各参数之间的关系。  相似文献   

10.
调谐质量阻尼器系统控制结构地震反应的若干问题   总被引:18,自引:3,他引:18  
本文研究调谐质量阻尼器(TunedMassDamper,以下简称TMD)用作抗震结构的防御体系时的一些问题,包括TMD在结构上的最佳位置,TMD频率的最佳值,TMD对非调谐结构振型的影响和TMD参数的灵敏度分析,这些问题的解决将为研究设置TMD的结构的抗震设计方法提供理论依据。  相似文献   

11.
以一座矮塔斜拉桥为研究对象,分析碰撞调谐质量阻尼器对于该结构的抑震效果。首先介绍了新型碰撞调谐质量阻尼器(Pounding Tuned Mass Damper,PTMD)的减震机理及基于接触单元的非线性碰撞力模型;之后,通过ANSYS软件中的APDL语言实现了PTMD减震系统的时域分析方法,并通过三条实际地震记录验证了PTMD的抑震效果。数值分析结果表明:(1)传统调谐质量阻尼器(tuned mass damper,TMD)及新型PTMD对于矮塔斜拉桥的位移、加速度及塔身弯矩响应均有较好的抑制效果;(2)PTMD相比传统TMD多了一种碰撞耗能模式,其减震效果略高于传统TMD。  相似文献   

12.
伸缩缝刚度对大跨度悬索桥动力特性的影响   总被引:1,自引:1,他引:0  
伸缩缝作为大跨度桥梁与引桥之间的重要连接构件,其抗推刚度及可能存在的变异性对主桥及引桥动力特性的影响不可忽略。本文建立了大跨度悬索桥及引桥的有限元模型,采用弹簧单元模拟加劲梁与引桥箱梁之间的伸缩缝,分析伸缩缝刚度对悬索桥及引桥自振特性及其地震响应的影响规律。分析结果表明:伸缩缝刚度对加劲梁的横弯振型、竖弯与纵飘耦合振型的频率有明显的影响;伸缩缝刚度的变化会导致加劲梁与引桥的振型相互耦合,同时这些振型的频率发生相应的突变,当伸缩缝刚度较大时,加劲梁两个竖弯与纵飘的耦合振型解耦成为独立的竖弯和纵飘振型;当引桥与悬索桥加劲梁的纵飘振型发生耦合时,在纵向和竖向地震作用下的悬索桥及引桥的地震响应达到最小。伸缩缝刚度对悬索桥动力特性影响的分析可为悬索桥的模态参数确认、损伤识别、抗震性能分析提供有价值的借鉴。  相似文献   

13.
自锚式悬索桥主桥动力特性分析   总被引:5,自引:1,他引:5  
以某自锚式悬索桥主桥为研究对象,采用M IDAS有限元程序,建立了该桥的空间力学计算模型,利用子空间迭代法计算了该桥梁结构的自振频率和振型,结合计算结果对桥梁的动力特性和刚度特点进行了讨论。计算结果可为该类型桥梁的设计、施工以及使用阶段的健康检测和维护提供技术参数和依据。  相似文献   

14.
This paper presents the variations of vibration under different traffic conditions on the Fatih Sultan Mehmet suspension bridge in Istanbul, Turkey.The main intention is to determine the vibration amplifications under heavy-traffic as opposed to no-traffic conditions. This is the first study in this particular area that has been performed on this bridge, over which an average of 200,000 cars pass daily. Two full-scale ambient vibration surveys were carried out on two different days to determine the response of the bridge to diverse traffic conditions. Initial measurements were taken as the bridge experienced heavy stress conditions caused by rush-hour traffic. Secondary measurements were recorded after closing the bridge to traffic. The data were analyzed to gauge the vibration effects of heavy-traffic conditions on the bridge and to determine the effects of different traffic conditions on the free vibration characteristics of the bridge. The analyses were performed utilizing different amplification methods. Results show that there are important differences in the amplifications of the vibration amplitudes. Especially heavy-traffic on the bridge causes the vibration response of the bridge to be intensified in comparison to no-traffic conditions. Additionally, predominant frequencies are shifted as a direct result of traffic load acting on the bridge. Even more importantly and is probably analogous for all long-span bridges, is the fact that any movement causing vibration on the bridge is carried and amplified along its length. These significant amplifications indicate the important effect of varying traffic loads and how the bridge responds to the diverse movements it experiences. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

15.
Ambient and forced vibration tests were carried out on the Beauharnois bridge, a unique, 177‐m combined suspension and cable‐stayed structure near Montreal, Canada. A rehabilitation program was completed on the bridge during which the deck was completely rebuilt with an orthotropic slab on two steel trusses. The rehabilitation program also included the addition of two pairs of stay cables on both towers, creating a hybrid suspension system. The paper presents a series of dynamic tests performed to evaluate the dynamic properties and the dynamic amplification factor (DAF) for the rehabilitated bridge. The experimental program involved the measurement of vertical, transverse, and longitudinal acceleration responses of the deck and tower under ambient and controlled traffic loads. Displacement, strain, and integrated acceleration DAFs were computed under different loading conditions. Modal properties were evaluated and used to correlate a three‐dimensional finite element model for the bridge, including non‐linear cable behaviour. The paper discusses the experimental setup as well as the techniques used to evaluate vibration frequencies, mode shapes, and the DAF. Correlation of numerical dynamic properties and experimental results is also presented. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   

16.
The optimum parameters of tuned mass dampers (TMD) that result in considerable reduction in the response of structures to seismic loading are presented. The criterion used to obtain the optimum parameters is to select, for a given mass ratio, the frequency (tuning) and damping ratios that would result in equal and large modal damping in the first two modes of vibration. The parameters are used to compute the response of several single and multi-degree-of-freedom structures with TMDs to different earthquake excitations. The results indicate that the use of the proposed parameters reduces the displacement and acceleration responses significantly. The method can also be used in vibration control of tall buildings using the so-called ‘mega-substructure configuration’, where substructures serve as vibration absorbers for the main structure. It is shown that by selecting the optimum TMD parameters as proposed in this paper, significant reduction in the response of tall buildings can be achieved. © 1997 John Wiley & Sons, Ltd.  相似文献   

17.
Tuned mass dampers(TMDs) have been widely used in recent years to mitigate structural vibration.However,the damping mechanisms employed in the TMDs are mostly based on viscous dampers,which have several well-known disadvantages,such as oil leakage and difficult adjustment of damping ratio for an operating TMD.Alternatively,eddy current damping(ECD) that does not require any contact with the main structure is a potential solution.This paper discusses the design,analysis,manufacture and testing of a large-scale horizontal TMD based on ECD.First,the theoretical model of ECD is formulated,then one large-scale horizontal TMD using ECD is constructed,and finally performance tests of the TMD are conducted.The test results show that the proposed TMD has a very low intrinsic damping ratio,while the damping ratio due to ECD is the dominant damping source,which can be as large as 15% in a proper configuration.In addition,the damping ratios estimated with the theoretical model are roughly consistent with those identified from the test results,and the source of this error is investigated.Moreover,it is demonstrated that the damping ratio in the proposed TMD can be easily adjusted by varying the air gap between permanent magnets and conductive plates.In view of practical applications,possible improvements and feasibility considerations for the proposed TMD are then discussed.It is confirmed that the proposed TMD with ECD is reliable and feasible for use in structural vibration control.  相似文献   

18.
建立了哪吒大桥———钢桁加劲梁悬索桥的三维有限元计算模型,对该桥进行了振动特性和地震响应研究,对比分析了一致激励下和考虑局部场地效应、行波效应非一致激励下的桥梁地震时程响应的差异。计算结果表明,由于悬索桥的钢桁加劲梁采用半飘浮体系,纵向约束较弱,桥梁第1阶振型为钢桁加劲梁的纵飘;各阶振型的频率呈现出密集分布的形态;考虑地震波传播速度产生的行波效应的影响,桥梁的地震响应与一致激励下的地震响应有一定差异;局部场地效应对哪吒大桥的地震响应影响较大,特别是对大缆应力及结构变形影响很大;哪吒大桥在7度设防(地震波峰值加速度不超过0.15g)时,大桥的抗震安全性是可以得到保证的。  相似文献   

19.
传统的调谐质量阻尼器(TMD)设计均仅针对结构某一阶模态单独设置,当用于密频结构减振时会导致附加质量过多。为减小TMD的附加质量,结合大跨度斜拉桥结构的密频与风致耦合振动特点,提出了一种新型的双向共享质量与电涡流阻尼式TMD。具体实现方式是:水平、竖向TMD的刚度构件分别采用悬臂梁与压簧,将水平向TMD整体置于压簧上面,从而构成竖向TMD的质量;导体板固定不动,使安装在TMD质量块的永磁体阵列随质量块竖向或水平方向运动,从而分别产生竖向与水平向的电磁涡流阻尼。研究结果表明:(1)电涡流阻尼可以很好地实现双向TMD装置的共享阻尼,且电涡流阻尼的大小可以很方便地调节;(2)采用双向TMD进行斜拉桥的风致振动控制减振效果良好,可行性强。  相似文献   

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