采用颗粒调谐质量阻尼器的钢框架结构振动台试验研究

通过附加和不附加颗粒调谐质量阻尼器的5层钢框架振动台试验,研究其在实际地震波以及上海人工波激励下的减震效果。通过调整不同悬挂长度（频率比）、质量比、颗粒到阻尼器壁净距等参数,分析阻尼器参数对其减震效果的影响。试验结果表明：不同地震作用下该类阻尼器均能达到较好的减震效果,其中上海人工波的减震效果最好;对于多层钢框架结构,阻尼器能够有效控制第1振型的振动,但是对于高阶振型的控制作用无法保证;当阻尼器频率与主体结构基频相同时,能够达到最优减震效果,而当二者频率不同时,依然有一定的减震效果,说明其具有一定的鲁棒性;在合适的质量比（0.66%）下,阻尼器能够达到最佳减震效果;当颗粒到容器内壁净距为1.6D~3.6D时,可使阻尼器响应最小,且减震效果较好。     

Shaking table model test of a mega‐frame with a vibration control substructure

A mega‐frame with a vibration control substructure (MFVCS) is a tuned mass damper system that converts substructures into a tuned mass. In this study, a kind of MFVCS using lead–rubber bearings (LRBs) to connect the vibration control substructure to the mega‐frame was proposed. To investigate the damping effect of this MFVCS, a series of shaking table tests were conducted, and the seismic responses of the MFVCS were compared with those of the traditional mega‐frame structure (TMFS). The results show that the seismic responses of the MFVCS are clearly smaller than those of the TMFS; additionally, the proposed MFVCS can provide a sufficient damping effect under different ground motions. Finite element (FE) models of the TMFS and MFVCS were established and validated by experimental results. Finally, the simulation results adopting different LRB models (equivalent linear and nonlinear elements) were compared, and the results indicate that simulation results can be obtained with greater accuracy from the FE model with a nonlinear LRB model than that with a linear LRB model.     

钢筋混凝土巨型框架结构及附单向TMD装置的减震结构振动台试验研究

为了研究钢筋混凝土巨型框架结构体系的抗震性能及其地震作用损伤机理,设计制作1/25的缩尺模型,并设计加工了一套调谐质量阻尼器（TMD）装置安装在模型结构顶部,进行振动台试验,得到结构的动力特性和位移响应,并对比分析了TMD的减震效果。结果表明：当在峰值加速度为0.140g的地震波作用后（相当于原型7度多遇地震）,模型结构处在弹性工作状态,在峰值加速度为0.400g的地震波作用后（相当于原型7度基本烈度）,模型结构出现轻微破坏,在峰值加速度为0.880g的地震波作用后（相当于原型7度罕遇地震）,模型结构出现中等破坏,该原型结构可以满足抗震设计的要求;TMD装置具有较好的减震效果。     

设置黏滞阻尼墙的钢框架结构振动台试验研究

以3层设置黏滞阻尼墙的钢框架结构为研究对象,对其进行3条地震波在不同水准下的振动台试验。通过对设置与不设置黏滞阻尼墙的两种结构动力特性和动力响应对比,分析了黏滞阻尼墙的减震效果和耗能特征及其变化规律。研究结果表明,黏滞阻尼墙是一种同时提供附加刚度和附加阻尼的被动消能减震装置,其在提供附加阻尼和附加刚度的同时可以对结构位移起到非常显著的控制作用,并且随着输入地震波峰值加速度的增大,该附加刚度逐渐减小,而附加阻尼则逐渐增大。此外,有限元分析结果与振动台试验结果的吻合度随响应对象和激励工况的不同而变化,说明了传统Maxwell模型用于模拟黏滞阻尼墙在动态力学特性方面的局限性。     

Influence of soil‐structure interaction on performance of a super tall building using a new eddy‐current tuned mass damper

Tuned mass dampers (TMDs) can be used as vibration control devices to improve the vibration performance of high‐rise buildings. The Shanghai Tower (SHT) is a 632‐m high landmark building in China, featuring a new eddy‐current TMD. Special protective mechanisms have been adopted to prevent excessively large amplitude of the TMD under extreme wind or earthquake loading scenarios. This paper presents a methodology for simulating behavior of the new eddy‐current TMD that features displacement‐dependent damping behavior. The TMD model was built into the SHT finite element model to perform frequency analysis and detailed response analyses under wind and earthquake loads. Furthermore, soil‐structure interaction (SSI) effects on wind and seismic load responses of the SHT model were investigated, as SSI has a significant impact on the vibration performance of high‐rise buildings. It was found that SSI has more significant effects on acceleration response for wind loads with a short return period than for wind loads with a long return period. Some of the acceleration responses with SSI effects exceed design limits of human comfort for wind loads with shorter return periods. As to the seismic analyses, it was found that SSI slightly reduces the displacement amplitude, the damping force, and the impact force of the TMD.     

钢筋混凝土框架结构模型模拟地震振动台试验

以4层附加柔性连接填充墙钢筋混凝土模型框架振动台试验为背景,设计并制作了1/8比例微粒混凝土整体结构模型,进行了模拟地震振动台试验研究,根据相似系数由模型结构试验结果反应反推原型结构的动力反应,结果表明,原型结构的层间位移与最大位移角均满足我国抗震规范要求。     

含软弱层大空间混凝土框架结构振动台试验

为研究现阶段存量较大的大型公共建筑结构强震作用下地震响应和抗震性能,针对一含软弱层的大空间RC框架结构,设计了几何相似比为1∶6的模型,开展设防烈度下多种激励的模拟地震动试验。通过对模型破坏形态、动力性能、加速度与位移响应等指标的测试分析,研究大空间混凝土(LRC)框架结构相对常规混凝土框架结构在动力响应与变形特征等方面的差异。试验研究与分析结果表明：LRC框架结构的损伤集中在软弱层,其柱端抗弯能力对整体结构的抗震性能影响最大;楼层加速度和相对位移经软弱层传递后易发生突变,LRC框架结构相对常规结构呈现出更明显的整体弯曲特征;含软弱层的LRC框架结构破坏等级的划分所依据的层间位移角限值相对常规RC框架结构需提高一级。     

Shaking table test on hybrid structure with SRC frame and steel frame strengthened concrete core tube

针对工程中采用的钢梁SRC柱框架-型钢混凝土核心筒混合结构的抗震性能进行了试验研究。设计并完成了一幢17层的1∶10模型结构,并对其进行了不同地震工况下振动台试验。分析了该结构体系固有动力特性以及在不同类型、不同强度水准的地震动输入下位移、速度、加速度响应及破坏机理;研究了布置于钢筋混凝土核心筒内的型钢框架对结构整体抗侧能力及变形性能的影响。结果表明：在不同类型、不同强度的地震动作用下,该结构体系的破坏始于型钢混凝土核心筒与外部钢梁SRC柱框架连接节点处,而后向核心筒体内部连梁发展,最终扩展到核心筒体。在核心筒体混凝土局部出现严重开裂破坏后,内置的型钢框架及外部的SRC钢梁框架仍处于弹性工作状态,表明该结构体系可实现多道防线的抗震设计目的且传力途径明确,抗震性能良好。     

子结构隔震的巨型框架结构地震反应分析与振动台试验研究

为考察基于子结构隔震的巨型框架结构的实际振动控制效果,对一巨型框架结构和采用子结构隔震的巨型框架结构进行数值分析和振动台试验。介绍了巨型框架结构原型,采用有限元方法对巨型框架结构和采用子结构隔震的巨型框架结构进行分析,研究子结构隔震技术对外部主框架和内部子框架的地震反应控制效果。介绍了缩尺模型结构及其试验方案,对其进行了模拟地震的振动台试验,测量和分析了主框架和子框架的地震反应。有限元分析和振动台试验结果表明：子框架隔震后,巨型框架结构的基本周期得到延长,但隔震结构前6阶振型的振动都是以子框架振动为主,而非隔震结构前6阶振型的振动都是以主框架的振动为主。子框架隔震后,主框架和子框架的地震反应都显著减小,位置较低的子框架2的地震反应及其隔震效果一般要比上部子框架3的大。隔震子框架的变形主要集中在隔震层上,但隔震层变形小于主、子框架间的隔震缝宽度。     

Shaking table test and numerical simulation on vibration control effects of TMD with different mass ratios on a super high‐rise structure

In this paper, the influence of mass ratio on the vibration control effects of tuned mass damper (TMD) on a super high‐rise building has been investigated. A 1/45 scaled model of a super high‐rise building was constructed, and the TMD with the mass ratio of 0.01, 0.02, and 0.03, respectively, was suspended on the top. Shaking table test and the corresponding numerical simulation were carried out to make a further understanding of the damping mechanism. The structural performance with or without TMD was comparatively studied. The results show that larger mass ratio can improve the control effects under frequent earthquake, but the control effects increase little with the increase of mass ratio under rare earthquake due to structural damages, accompanied by stiffness degradation and nonlinear behavior of the main structure. In addition, some suggestions on the mass ratio selection are also proposed to generalize its applications.     

Coupled shear‐flexural model for dynamic analysis of fixed‐base tall buildings with tuned mass dampers

An equivalent discrete model is developed for time domain dynamic analysis of uniform high‐rise shear wall‐frame buildings with fixed base and carrying any number of tuned mass dampers (TMDs). The equivalent model consists of a flexural cantilever beam and a shear cantilever beam connected in parallel by a finite number of axially rigid members that allow the consideration of intermediate modes of lateral deformation. The proposed model was validated by a building whose lateral resisting system consists of a combination of shear walls and braced frames. The results showed the effectiveness of TMDs to reduce the peak displacements, interstory drift ratio, and accelerations when the building is subjected to a seismic load. The root mean square accelerations due to along‐wind loads also decrease if TMDs are attached to the building.     

Coupled‐two‐beam discrete model for dynamic analysis of tall buildings with tuned mass dampers including soil–structure interaction

An equivalent coupled‐two‐beam discrete model is developed for time‐domain dynamic analysis of high‐rise buildings with flexible base and carrying any number of tuned mass dampers (TMDs). The equivalent model consists of a flexural cantilever beam and a shear cantilever beam connected in parallel by a finite number of axially rigid members that allows the consideration of intermediate modes of lateral deformation. The equivalent model is applied to a shear wall–frame building located in the Valley of Mexico, where the effects of soil–structure interaction (SSI) are important. The effects of SSI and TMDs on the dynamic properties of the shear wall–frame building are shown considering four types of soil (hard rock, dense soil, stiff soil, and soft soil) and two passive damping systems: a single TMD on its top (1‐TMD) and five uniformly distributed TMDs (5‐TMD). The results showed a great effectiveness of the TMDs to reduce the lateral seismic response and along‐wind response of the shear wall–frame building for all types of soils. Generally speaking, the dynamic response increases as the flexibility of the foundation increases.     

某高度522m超高层结构振动台试验与理论分析研究

为验证8度抗震设防烈度区某522 m超高层结构的抗震性能,设计并制作了1/40缩尺结构模型,通过模拟地震振动台试验,研究结构在8度多遇、设防、罕遇地震作用下的动力特性,考察其在单向和三向地震动输入下的变形及损伤情况。此外,采用ABAQUS软件对结构进行了8度罕遇地震作用下弹塑性时程分析,考察了结构动力特性和位移反应,分析结构的损伤状态和薄弱部位,并与振动台试验结果对比。结果表明,该结构采用的巨型柱、巨型斜撑与环带桁架的外框筒和型钢-混凝土组合结构核心筒形成的双重结构抗侧力体系,具有较好的稳定性和结构效能,该结构在8度(0.3g)罕遇地震作用下未发生倒塌,能够很好地满足“小震不坏、大震不倒”的性能要求。     

Shaking table model test and numerical analysis of a long‐span cantilevered structure

This paper presents an earthquake‐resistance study program of a long‐span cantilevered story building. The program consists of a shaking table test study and nonlinear seismic analysis using finite element modeling technique. A 1/30 scale model of the prototype structure was designed and manufactured and then tested via the shaking table facility. Dynamic responses of the prototype structure under different earthquake excitation loadings were simulated. Dynamic properties, acceleration, and deformation responses of the scale down model under different intensity levels of earthquake were studied. The dynamic behavior, cracking pattern, and the likely governing failure mechanism of the structure were analyzed and discussed as well. The seismic responses of the prototype building were deduced and analyzed in terms of the similitude law. Furthermore, elaborate finite element models were established, and nonlinear numerical analysis of the prototype structure was conducted. The errors in the seismic response of the structure caused by structural simplification of scale down modeling are found small, and the dynamic behavior of the structure was not altered in the earthquake excitations. This test study provides a benchmark to calibrate the finite element model and a tentative guide in seismic design of such long‐span cantilevered story buildings.     

附加PTMD风力发电机结构减振控制试验研究

通过开展附加颗粒调谐质量阻尼器(particle tuned mass damper, PTMD)风力发电机结构模型的自由振动试验和振动台试验,研究PTMD自身参数对其减振性能的影响规律,检验PTMD用于降低风力发电机结构不利振动的合理性与有效性,揭示随机激励下耦合系统的工作机理。借助自由振动试验研究了设计参数对PTMD减振性能的影响规律,初步确定了系统的参数配置。同时,通过地震波激励工况、风荷载激励工况和风-地震耦合荷载激励工况对风力发电机结构使用PTMD进行振动控制的合理性与有效性进行了检验,进一步揭示随机激励下耦合系统的减振机理。试验结果表明：颗粒-腔体质量比和频率比参数分别取值0.27和0.97时PTMD表现出较好的减振性能;3种随机激励下PTMD能够有效抑制风力发电机结构的动力响应,其中,El Centro波作用下,PTMD对结构顶部加速度和位移峰值响应的控制效果分别为5.52%和7.73%,而对均方根响应的控制效果则高达33.3%和32.08%。由此可见,PTMD对均方根响应的控制效果优于峰值响应。对比传统调谐质量阻尼器(TMD)结果可知,经合理设计的PTMD具有更佳的减振...     

Improving the wind‐induced human comfort of the Beijing Olympic Tower by a double‐stage pendulum tuned mass damper

With five sub towers and a maximum height of 246.8 m, the Beijing Olympic Tower (BOT) is a landmark of Beijing. The complex structural properties and slenderness of the BOT render it prone to wind loading. As far as the wind‐induced performance of this structure is concerned, this paper thus aims at a tuned mass damper‐based mitigation system for controlling the wind‐induced acceleration response of the BOT. To this end, the three‐dimensional wind loading of various wind directions are simulated based on the fluctuating wind force obtained by the wind tunnel test, by which the wind‐induced vibration is evaluated in the time domain by using the finite element model. A double‐stage pendulum tuned mass damper (DPTMD), which is capable of controlling the long period dynamic response and requires only a limited space of installation, is optimally designed at the upper part of the tower. Finally, the wind‐induced response of the structure with and without DPTMD is compared with respect to various wind directions and in both the time and frequency domains. The comparative results show that the wind‐induced accelerations atop the tower with the wind directions of 45, 135, 225, and 315° are larger than those with the other directions. The DPTMD significantly reduces the wind‐induced response by the maximum acceleration reduction ratio of 30.05%. Moreover, it is revealed that the control effect varies noticeably for the five sub towers, depending on the connection rigidity between Tower1 and each sub tower.     

Parametric study of the use and optimization of tuned mass dampers to control the wind‐ and seismic‐induced responses of a slender monument

Passive energy dissipation devices have been used around the world to mitigate the response of structures under dynamic excitations, such as wind or seismic loading. The use of tuned mass dampers (TMD) in tall and slender buildings to reduce unwanted responses has proved to be very effective. The main purpose of this work is to study the structural behavior of a 115‐m‐height slender monument fitted with TMDs subjected to simulated wind and seismic loading. Turbulent wind forces were calculated based on samples of turbulent wind speed simulated with an auto regressive and moving average (ARMA) model. Ground motions compatible with a seismic site spectrum were also simulated. An optimization approach is suggested to determine the parameters of the TMDs that reduce the structural response to the maximum. The effectiveness of the TMDs for reducing the structural response of the monument is discussed in detail, and the use of optimally tuned TMDs is emphasized.     

边坡动力破坏特征的振动台模型试验与数值分析

采用大型振动台模型试验,输入幅值逐级增大的地震波,直到边坡破坏,得到边坡动力破坏特征:上部拉裂缝和下部剪切滑移面形成贯通的破裂面,滑体上监测点位移和加速度响应突变,表明边坡已经发生破坏,且坡顶局部块体在地震作用下发生抛射现象。采用FLAC动力差分软件通过逐渐加大输入地震波幅值,模拟模型边坡振动台试验过程,证实拉裂缝与剪切滑移面贯通是边坡动力破坏的必要条件,位移和加速度响应突变可以作为边坡动力破坏的判据。振动台试验和数值计算在边坡动力破坏三个特征上吻合较好,证明振动台模型试验结果的合理性,也证明数值分析方法的可靠性。     

Seismic response of self‐centering precast concrete frames with hysteretic dampers

With the rapid development of cities and the invasion of major natural disasters such as earthquakes, the resilience city as a new design concept has been paid more and more attention. As an important branch of self‐centering seismic resisting system, self‐centering concrete frame system has been studied by many scholars. These studies prove that self‐centering concrete frame structure has excellent self‐centering ability but poor energy dissipation capacity. Adhering to the working principle of self‐centering structure and considering the development concepts of building industrialization and modularization, this paper proposed a kind of self‐centering precast concrete frame with hysteretic damper (SCPCHD). In order to verify its energy dissipation capacity and seismic performance, elaborate finite element models were established and elastoplastic dynamic time history analyses were carried out. The results showed that the SCPCHD frame has a similar interstory displacement response to the reinforced concrete (RC) frame and the energy dissipation performance of its joint is obviously superior to the RC frame under rare earthquake because the SCPCHD frame has low damage characteristics and excellent damping device. In summary, this paper proves the feasibility and superiority of the SCPCHD frame, providing reliable support for further research.     

Seismic fragility analysis of concrete encased frame‐reinforced concrete core tube hybrid structure based on quasi‐static cyclic test

Concrete‐encased frame‐core tube hybrid structural system has been widely employed in high‐rise buildings. This paper intends to analyze the seismic fragility of this structural system under ground motion excitation. The quasistatic cyclic test on a 1/5‐scaled, 10‐story three‐bay specimen is introduced. Fiber‐based finite element model is developed and integrated with numerical techniques that would be able to simulate the nonlinear response based on the OpenSees program. As the model is verified by the experimental data, a series of incremental dynamic analyses (IDAs) considering different frame‐tube stiffness ratios are carried out. IDA curves are drawn to describe each structural performance state. Fragility curves and probabilistic demand models are proposed for quantifying failure probability. The collapse margin ratio is employed to evaluate the collapse probability. The result shows that the collapse probability under rare earthquake still meets the requirement of Applied Technology Committee‐63 Report. The hybrid structure is proved to perform superior collapse resistance ability. The proper increase in the stiffness of core tube can reduce the collapse probability and enhance the collapse resistance capacity.