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1.
针对风电塔架结构内部有限的空间,设计一种新型减振系统。基于悬吊质量摆减振原理,利用形状记忆合金（SMA）的超弹性特性,将SMA丝与弹簧叠加成SMA阻尼器后并与悬吊质量摆复合,设计了一种形状记忆合金-悬吊质量摆阻尼器（SMA-SMPD）系统。研究了细部构造、减振原理和参数影响,并利用Matlab软件对单自由度体系在不同地震作用下的动力响应进行了数值模拟。结果表明:所设计的刚度和质量可调的SMA-SMPD是有效的。与结构受控频率相调时,将结构振动能量集中转换到SMA-SMPD上,可耗散结构振动能量,减震率可达30%~40%,且整体性能稳定,对结构动力响应控制效果显著。 相似文献
2.
本文从控制装置实现角度，研究了调谐质量阻尼控制装置的关键技术，其中包括装置的支撑系统、气压弹簧和液压阻尼器。应用这些技术研究了在地王大厦安装HMD装置控制结构风振响应，解决了地王大厦在风荷载作用下总侧移和层间位移角超出我国规范限值的问题。在准确把握结构动力特性和设计准则的前提下，对控制装置的参数进行了设计。系统仿真分析表明，HMD控制装置在地王大厦上应用可以有效降低结构侧向位移。 相似文献
3.
This paper presents a study on the behaviour of rectangular liquid dampers under a horizontal excitation of arbitrary time history. The theoretical model to predict motion of a shallow liquid in a rectangular tank is adapted from a previous researchers' model which was developed for sinusoidal excitations. The model includes an energy dissipation term arising from liquid viscosity. In the present consideration of arbitrary excitations, the energy dissipation term is derived in a straightforward way, without resorting to the equivalent linearization method or assumption of harmonic response as used by earlier researchers. The up-crossing rate of wave height is used in furnishing the Reynolds number required for the evaluation of shear stress in the boundary layer. Since there was no known precedent study involving arbitrary excitations, experiments have been performed accordingly to verify the model. Generally, the theoretical model furnishes results which are found to be in close agreement with the experimental ones. The results also illustrate the strong dependency of liquid motion upon the natural frequency of the damper, amplitude and frequency content of the excitation spectrum. The model is then applied to study the effectiveness of tuned liquid dampers in vibration control of a single-degree-of-freedom structure subjected to earthquake excitations. Significant suppression of structural vibration can be achieved using tuned liquid dampers. 相似文献
4.
This paper presents a theoretical investigation on the performance of multiple‐tuned liquid column dampers (MTLCD) for reducing torsional vibration of structures in comparison with single‐tuned liquid column dampers (STLCD). The analytical model is first developed for torsional vibration of a structure with an MTLCD under either harmonic excitation or white noise excitation. The experimental results are then used to verify the analytical model for coupled MTLCD‐structure systems under harmonic excitation. The performance of an MTLCD and its beneficial parameters for achieving the maximum torsional response reduction to white noise excitation are finally investigated through an extensive parametric study in terms of the distance from the centre line of the MTLCD to the rotational axis of the structure, the ratio of the horizontal length to the total length of liquid column, frequency bandwidth, head‐loss coefficient, the number of TLCD units in an MTLCD, frequency‐turning ratio and the spectral level of excitation moment. The results show that there is an optimal head‐loss coefficient and an optimal frequency bandwidth for an MTLCD to achieve the maximum torsional response reduction. It is also demonstrated that the sensitivity of an optimized MTLCD to the frequency‐tuning ratio is less than that of an optimized STLCD, and it can be further improved by increasing the bandwidth but at the cost of less torsional vibration reduction. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
5.
In this study, several mass dampers were designed and fabricated to suppress the seismic responses of a ¼‐scale three‐storey building structure. The dynamic properties of the dampers and structure were identified from free and forced vibration tests. The building structure with or without the dampers was, respectively, tested on a shake table under the white noise excitation, the scaled 1940 El Centro earthquake and the scaled 1952 Taft earthquake. The dampers were placed on the building floors using the sequential procedure developed by the authors in previous studies. Experimental results indicated that the multiple damper system is substantially superior to a single tuned mass damper in mitigating the floor accelerations even though the multiple dampers are sub‐optimal in terms of tuning frequency, damping and placement. These results validated the sequential procedure for placement of the multiple dampers. The structure was also analysed numerically based on the shake table excitation and the identified structure and damper parameters for all test cases. Numerical and experimental results are in good agreement, validating the dynamic properties identified. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
6.
Optimum geometry of tuned liquid column-gas damper for control of offshore jacket platform vibrations under seismic excitation 总被引：1，自引：1，他引：0
In this study, the effectiveness of a tuned liquid column-gas damper, TLCGD, on the suppression of seismic-induced vibrations of steel jacket platforms is evaluated. TLCGD is an interesting choice in the case of jacket platforms because it is possible to use the structural elements as the horizontal column of the TLCGD. The objective here is to find the optimum geometric parameters, namely orientation and configuration of vertical columns, length ratio, and area ratio of the TLCGD, considering nonlinear damping of the TLCGD and water-structure interaction between the jacket platform and sea water. The effects of different characteristics of ground motion such as PGA and frequency content on the optimum geometry are also investigated and it is observed that these features have some influence on the optimum area ratio. Finally it is observed that pulse arrangement of ground acceleration is one of the most important parameters affecting the efficiency of a TLCGD. In other words, it is found that the TLCGD’s capability to reduce the RMS responses depends only on the frequency content of the ground acceleration, but its capability to reduce the maximum responses depends on both the frequency content and the pulse arrangement of the ground acceleration. 相似文献
7.
A wind turbine system equipped with a tuned liquid column damper(TLCD) is comprehensively studied via shaking table tests using a 1/13-scaled model. The effects of wind and wave actions are considered by inputting responseequivalent accelerations on the shaking table. The test results show that the control effect of the TLCD system is significant in reducing the responses under both wind-wave equivalent loads and ground motions, but obviously varies for different inputs. Further, a blade-hub-tower integrated numerical model for the wind turbine system is established. The model is capable of considering the rotational effect of blades by combining Kane’s equation with the finite element method. The responses of the wind tower equipped with TLCD devices are numerically obtained and compared to the test results, showing that under both controlled and uncontrolled conditions with and without blades’ rotation, the corresponding responses exhibit good agreement. This demonstrates that the proposed numerical model performs well in capturing the wind-wave coupled response of the offshore wind turbine systems under control. Both numerical and experimental results show that the TLCD system can significantly reduce the structural response and thus improve the safety and serviceability of the offshore wind turbine tower systems. Additional issues that require further study are discussed. 相似文献
8.
As high‐rise buildings are built taller and more slender, their dynamic behavior becomes an increasingly critical design consideration. Wind‐induced vibrations cause an increase in the lateral wind design loads, but more importantly, they can be perceived by building occupants, creating levels of discomfort ranging from minor annoyance to severe motion sickness. The current techniques to address wind vibration perception include stiffening the lateral load‐resisting system, adding mass to the building, reducing the number of stories, or incorporating a vibration absorber at the top of the building; each solution has significant economic consequences for builders. Significant distributed damage is also expected in tall buildings under severe seismic loading, as a result of the ductile seismic design philosophy that is widely used for such structures. In this paper, the viscoelastic coupling damper (VCD) that was developed at the University of Toronto to increase the level of inherent damping of tall coupled shear wall buildings to control wind‐induced and earthquake‐induced dynamic vibrations is introduced. Damping is provided by incorporating VCDs in lieu of coupling beams in common structural configurations and therefore does not occupy any valuable architectural space, while mitigating building tenant vibration perception problems and reducing both the wind and earthquake responses of the structure. This paper provides an overview of this newly proposed system, its development, and its performance benefits as well as the overall seismic and wind design philosophy that it encompasses. Two tall building case studies incorporating VCDs are presented to demonstrate how the system results in more efficient designs. In the examples that are presented, the focus is on the wind and moderate earthquake responses that often govern the design of such tall slender structures while reference is made to other studies where the response of the system under severe seismic loading conditions is examined in more detail and where results from tests conducted on the viscoelastic material and the VCDs in full‐scale are presented. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
9.
大底盘多塔超过一定高度时属于复杂超高限结构,这类结构风工程研究多涉及风洞试验或理论研究,过程复杂且应用局限。以宁夏悦海新天地为工程背景,在ETABS建立悦海新天地双塔模型为风控对象。在空间相关性基础上,以自回归过滤技术模拟10a、50a和100a重现期风压下随机脉动风载。由相关资料确定研究对象最不利风向角,在该风向角下动力输入模拟脉动风载。对双塔结构分塔定义,输出T1和T2两个方向风振响应。结合工程提出在设备层布设5种不同黏滞阻尼器位移增效机构,确定最优安装形式。并对比在设备层以最优安装形式布设黏滞阻尼器位移增效机构、顶层布设多调谐质量阻尼器和混合控制法的减振效果。结果表明:3种风振控制措施均有效衰减结构风致振动,其中混合控制法为优控方案。 相似文献
10.
为了研究设备所在楼层位置对设备-结构相互作用的影响,以某高层钢框架为例,将设备分别放置于结构顶层和底层设计了2种设备-结构体系模型,然后利用ANSYS有限元分析软件对整体模型进行地震响应时程分析。分析结果表明:在El Centro波、Taft波和人工波作用下,当设备频率与结构基频调谐时,设备-结构相互作用会令结构动力响应减小而设备动力响应显著增大;设备-结构相互作用的大小与设备所在楼层密切相关:顶层设备与结构间的相互作用比底层更加剧烈,这与位于不同楼层的设备间等效质量以及底端输入激励频谱的差异有关。 相似文献
11.
风电塔是一种顶部有较大偏心质量的高耸薄壁悬臂结构,以某1.5MW水平轴三叶片风电塔为研究对象,重点关注风电塔振动台试验缩尺模型设计。根据量纲分析理论和相似条件,基于模型质量分布和刚度分布等效原则,设计模型塔筒截面及附加质量,保证模型与原型结构自振频率和振型相似。通过对比分析模型动力特性测试结果与原型实测结果,验证了该模型设计方法的合理性,可为同类型风电塔振动台试验设计提供参考与依据。针对该柔性对称高塔模型在动力特性测试中出现的正交耦合振动及拍振现象也进行了详细阐述。 相似文献
12.
A tuned liquid damper (TLD), which consists of rigid tanks partially filled by liquid, is a type of passive control device relying upon liquid sloshing forces or moments to change the dynamical properties and to dissipate vibrational energy of a structure. An analytical non-linear model is proposed for a TLD using rectangular tanks filled with shallow liquid under pitching vibration, utilizing a shallow water wave theory. The model includes the linear damping of the sloshing liquid, which is an important parameter in the study of a TLD as it affects the efficiency of the TLD. Shaking table experiments were conducted for verification; good agreement between the analytical simulations and the experimental results was observed in a small excitation amplitude range. The simulations of TLD-structure interaction by using the proposed model show that the TLD can efficiently suppress resonant pitching vibration of a structure. It is also found that the effectiveness of a TLD for suppressing the pitching vibration depends not only on the mass of liquid in the TLD but also on the configuration of the liquid as well as upon the position where the TLD is located. If the configuration of the liquid, i.e. the liquid depth and the TLD tank size, is designed suitably, the TLD can have a large suppressing moment and can be very effective even with a small mass of liquid. 相似文献
13.
土木工程结构鲁棒控制的发展 总被引：1，自引：0，他引：1
评述了结构控制的发展,指出发展结构鲁棒控制策略的重要性。重点评述了结构双重调谐质量阻尼器(DTMD)和多重双重调谐质量阻尼器(MDTMD)的控制策略,提出了需进一步发展主动双重调谐质量阻尼器(ADTMD)和主动多重双重调谐质量阻尼器(AMDTMD)控制策略、此外,评述了结构鲁棒控制的设计准则与高层建筑和大跨桥梁在风与地震作用下的统一自适应主动鲁棒控制策略。 相似文献
14.
本文提出了圆球减振装置对风力发电高塔振动控制的工作原理和计算方法,并对其控制效果进行了理论研究。首先利用拉格朗日方程推导得到圆球减振装置的自振频率及其对单自由度系统的被动控制力,并推广至多自由度系统。进而将风力发电高塔等效为集中质点模型,建立了风塔-减振装置体系的运动微分方程。用谐波叠加法模拟得到脉动风速时程,分析比较了风力发电高塔在无控及有控状态下的动力响应及疲劳寿命。计算结果表明,圆球减振装置是一种简单、经济和实用的减振装置,能够有效减小风塔的动力响应,延长其疲劳寿命。 相似文献
15.
Experimental and analytical study on the performance of particle tuned mass dampers under seismic excitation 
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下载免费PDF全文 A particle tuned mass damper (PTMD), which is a creative integration of a traditional tuned mass damper and an efficient particle damper in the vibration control area, is proposed. This paper presents a comprehensive study that involves experimental, analytical, and computational approaches. The vibration control effects of a PTMD that is attached to a five‐story steel frame under seismic input are investigated by a series of shaking table tests. The influence of some parameters (auxiliary mass ratio, gap clearance, mass ratio of particles to the total auxiliary mass, frequency characteristics, and amplitude level of the input) is explored, and the performance of the PTMD with/without buffered material is compared. The experimental results show that the PTMD can achieve significant damping effects under seismic excitations, and the bandwidth of the suppression frequency is expanded, showing the device's robustness and control efficiency. In addition, an approximately analytical solution that is based on the concept of an equivalent single‐particle damper is presented, and the method to determine the corresponding system parameters is introduced. A comparative study between experimental and numerical results is conducted to verify the feasibility and accuracy of this analytical model. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
16.
大型浅水湖泊太湖波浪特征及其对风场的敏感性分析 总被引：4，自引：2，他引：2
以空间均匀的实际风场为驱动,利用SWAN模式模拟了太湖波浪场,结果表明:SWAN模式能够较好的模拟太湖波浪的生成与传播,适用于大型浅水湖泊(太湖);同时分析了该风场驱动下下太湖风浪谱,波浪的绝对频率主要集中在0.45～1.0 Hz的中高频率段;风向与波向具有高度一致性.在同一风速下,太湖不同区域波浪成长稳定时间不同,湖心区稳定的谱峰频率在0.342～0.585 Hz之间,湾区及西山岛附近狭长水域稳定的谱峰频率在0.447～0.765 Hz之间;在同一区域,风速增大,波浪稳定时间减少,谱峰频率沿低频推移,在湖心区谱峰频率最小不低于0.340 Hz,湾区、西山岛附近狭长水域最小不低于0.447 Hz;风向的改变对湾区及西山岛附近狭长水域的波浪频谱形状影响较大. 相似文献
17.
In this paper, wind-induced vibration control of a single column tower of a cable-stayed bridge with a multistage pendulum mass damper (MSPMD) is investigated. Special attention is given to overcoming space limitations for installing the control device in the tower and the effect of varying natural frequency of the towers during construction. First,the finite element model of the bridge during its construction and the basic equation of motion of the MSPMD are introduced.The equation of motion of the bridge with the MSPMD under along-wind excitation is then established. Finally, a numerical simulation and parametric study are conducted to assess the effectiveness of the control system for reducing the wind-induced vibration of the bridge towers during construction. The numerical simulation results show that the MSPMD is practical and effective for reducing the along-wind response of the single column tower, can be installed in a small area of the tower, and complies with the time-variant characteristics of the bridge during its entire construction stage. 相似文献
18.
近年来,各地纷纷兴建大型火车站房,这类建筑中的楼盖大多为大跨、轻质和低阻尼结构,本文基于人体舒适度考虑,对这些大跨楼盖进行振动舒适度的分析。首先,建立某大型火车站房的整体有限元模型,研究这类建筑中大跨楼盖的振动特性;随后,对楼盖在各种不利工况人群荷载作用下的振动舒适度进行分析;最后,在已有研究的基础上,提出了大跨楼盖多重调谐质量阻尼器（Multiple Tuned Mass Dampers,简称MTMD）减振设计方法。结果表明,利用该方法设计MTMD减振系统,可以有效地控制大跨楼盖的竖向振动,各工况下的平均减振率可达34%,从而使结构在使用时满足人体舒适度的要求。 相似文献
19.
随着城市人口的增加,越来越多的超高层建筑在中国各大城市涌现,在其全寿命周期内不可避免的会遭受风甚至地震等多灾害的作用。以上海中心大厦为分析模型,根据其场地条件,采用Benowitez在2015年提出的1种基于随机波的模型方法模拟不同高度处具有空间相关性的脉动风荷载时程。通过对Perform 3D有限元软件建立的上海中心大厦模型进行非线性动力时程分析,研究地震和风耦合作用下对于结构性能的影响,并基于多灾害需求生成结构在地震和风耦合作用下的易损性曲面来研究结构的抗振可靠度。结果表明:结构的响应和易损性随着风速和PGA的增大而显著增大;随着风速的增大结构的响应和易损性均有增大的趋势,但随着地震动的增大,风荷载对结构响应和易损性影响逐步减小。 相似文献
20.
大连国贸大厦高层水箱风振控制研究及应用 总被引：3，自引：1，他引：2
本文针对一实际工程结构———大连国贸大厦,研究了风荷载作用下调液阻尼器的减振控制作用。首先建立了该结构的简化计算模型,利用Davenport谱给出了模拟风荷载。在大厦所处位置进行多次测量,得到实际风速样本。选取其中风速较大、过程平稳的样本,对实测样本和模拟样本的频谱进行比较,验证了模拟风荷载的合理性。文中将大厦顶层的生活水箱设计成可减小结构位移及加速度反应的控制装置TLD(tuned liqu id damper),根据不同工况进行数值计算,选出最佳方案,设计出可实际应用、并达到一定减振效果的减振水箱,以提高大厦在风荷载作用下的舒适度。 相似文献