钢筋混凝土巨型框架结构振动台试验分析与研究

发布时间：2018-04-09 20:17

本文选题：巨型框架　切入点：振动台试验　出处：《合肥工业大学》2015年博士论文

【摘要】：钢筋混凝土巨型框架结构是由主框架次框架组成的结构体系。主框架是由大型结构单元如巨型梁和巨型柱组成,巨型梁通常为一至两层层高的梁,巨型梁可以是实腹梁也可以是桁架梁；巨型柱可以是实腹柱也可以是巨型筒。巨型框架结构整体刚度大、传力明确、能充分发挥高强混凝土的强度高性能、具有良好的经济性能,是一种非常有发展前途的结构形式。目前针对巨型框架结构的振动台试验研究较少,本文依托国家自然科学基金委课题项目“超高层巨型框架结构弹塑性地震反应与能量分析的研究”,在课题组成员的共同协作下,依据相关规范以及PKPM软件设计了一201m高的55层钢筋混凝土巨型框架结构。本文以此结构为原型结构完成了一巨型框架缩尺模型结构的振动台试验,根据试验结果进行了详细的试验研究和理论分析。本文主要研究成果如下：(1)详细介绍了相似理论的三个相似定理,并且分析了如何运用一致相似律及似量纲分析法等相似理论设计振动台试验缩尺模型。(2)研究了多个超高层建筑结构缩尺模型在振动台试验中的各工况下的频率及刚度变化,研究结果表明振动台试验能反映原型结构的抗震设防水准要求。(3)为了验证钢筋混凝土巨型框架的抗震效果,以课题组设计的巨型框架结构为原型结构,设计了缩尺比为1/25的缩尺模型,在土木工程防灾国家重点实验室(同济大学)进行了模型制作与振动台试验。同时,完成了地震动及白噪声工况的选择、附加质量的计算等工作。(4)基于振动台试验结果,研究了试验模型在7度多遇、7度基本及7度罕遇烈度地震动作用下的动力响应、结构的破坏形式和破坏机理,同时利用振型MAC法进行了模型结构的损伤判断,研究结果表明按相关规范设计的巨型框架结构能满足抗震设防要求。(5)为了验证在调谐质量阻尼器(TMD-Tuned Mass Damper)作用下巨型框架的减震效果,在缩尺模型顶部安装了一个TMD装置,根据试验结果对比了减震下与非减震下的结构性能,对比结果表明TMD减震效果较为明显。(6)分析了不同频率段的地震动对结构位移反应的影响,理论及试验研究表明,El Centro、Chi Chi及汶川地震动作用下模型结构顶层位移主要是由结构第一频率的1/2-2倍频率范围内的地震动信号引起的。(7)基于试验数据进行了巨型框架结构的模态分析,分别应用峰值法、功率谱法及复模态最小二乘法求出了模型的结构频率、频响函数及阻尼。同时,基于位移信号的平均正则化功率谱密度的峰值,可较为准确地判断结构在哪个工况下发生严重的损伤。(8)应用ABAQUS软件对缩尺模型进行数值模拟研究,软件与试验结果的对比研究表明：数值模拟对振动台试验缩尺模型的适用性；同时数值模拟也表明了TMD对钢筋混凝土巨型框架结构的减震效果较好。
[Abstract]:Reinforced concrete mega-frame structure is a structure system composed of main frame and sub-frame.The main frame is composed of large structural elements such as giant beam and giant column. Giant beam is usually a beam with one or two layers of height, giant beam can be a full web beam or a truss beam, and a giant column can be a solid column or a giant tube.The mega-frame structure has the advantages of large stiffness, clear transmission of force, high strength and high performance of high-strength concrete, and good economic performance. It is a very promising structural form.At present, there is little research on shaking table test of mega-frame structures. This paper relies on the project of the National Natural Science Foundation of China, "the study of Elastoplastic Seismic response and Energy Analysis of Super-tall Mega-frame structures".A 201m high 55 story reinforced concrete mega frame structure is designed according to the related codes and PKPM software.In this paper, a shaking table test of a mega frame scale model structure is completed with this structure as the prototype, and the detailed experimental research and theoretical analysis are carried out according to the experimental results.The main research results of this paper are as follows: (1) the three similarity theorems of similarity theory are introduced in detail.And how to design the scale model of shaking table test by using the similarity theory such as uniform similarity law and similar dimensional analysis method is analyzed. The frequency and stiffness changes of several super tall building structure scale models under various working conditions of shaking table test are studied.The results show that the shaking table test can reflect the requirements of seismic fortification level of the prototype structure. In order to verify the seismic effect of the reinforced concrete mega-frame, the mega-frame structure designed by the research group is taken as the prototype structure.A scale model with a scale ratio of 1 / 25 is designed. The model making and shaking table test are carried out in the State key Laboratory of Civil Engineering disaster Prevention (Tongji University).At the same time, the damage of the model structure is judged by the mode MAC method.The results show that the mega frame structure designed according to the relevant codes can meet the requirements of seismic fortification. In order to verify the shock absorption effect of the mega-frame under the action of tuned mass damper (TMD-Tuned Mass damper), a TMD device is installed on the top of the scale model.According to the experimental results, the structural performance under shock absorption and non-shock absorption is compared. The results show that the effect of TMD on the displacement response of the structure is obvious. (6) the influence of ground motion at different frequencies on the displacement response of the structure is analyzed.The theoretical and experimental studies show that the top floor displacement of the model structure under the action of El Centro Chi Chi and Wenchuan earthquake is mainly caused by the ground motion signal in the frequency range of 1 / 2 to 2 times of the first frequency of the structure.Modal analysis of structures,The structure frequency, frequency response function and damping of the model are obtained by using the peak value method, the power spectrum method and the complex mode least square method, respectively.At the same time, based on the peak value of the average regularized power spectral density of the displacement signal, the structure can be accurately determined under which condition the serious damage occurs. The numerical simulation of the scale model is carried out by using ABAQUS software.The comparison between the software and the test results shows that the numerical simulation is applicable to the scale model of shaking table test, and the numerical simulation also shows that TMD has good seismic absorption effect on the reinforced concrete mega-frame structure.
【学位授予单位】：合肥工业大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TU973.15

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