【作者】 谢凡；

【导师】 沈蒲生；

【作者基本信息】 湖南大学 ， 结构工程， 2011， 博士

【摘要】 为了充分发挥钢和混凝土各自的优点,由钢框架–钢筋混凝土剪力墙(核心筒)或型钢混凝土框架–钢筋混凝土剪力墙(核心筒)组成的高层混合结构成为近年来在我国迅速发展的一种新型高层建筑结构体系。高层混合结构抗震性能的好坏无疑是该结构体系能否得到广泛推广的一个重要依据。通过结构设计将高层混合结构的地震反应完全限制在弹性阶段是极为不经济的,因此结构体系在地震作用下的反应分析,尤其是大震作用下,结构体系进入弹塑性阶段的反应分析成为近年来学者们研究的重点。本文利用低周反复加载试验对高层混合结构层模型的抗震性能进行研究,然后针对高层混合结构计算模型,在已有研究成果的基础上,对高层混合结构弹塑性地震反应分析做进一步的研究和改进,主要围绕构件非线性单元模型的建立和算法的选择进行讨论,并对部分结构形式的简化非线性分析方法进行适度的探讨,着重在以下几个方面:1.完成了6个不同类型的高层混合结构层模型结构低周反复加载试验研究,得到了各个试件的滞回曲线。从各个试件的滞回曲线中可以看出钢框架–混凝土剪力墙结构以及型钢混凝土框架–混凝土剪力墙结构的抗震性能要优于钢筋混凝土框架–混凝土剪力墙结构。通过改变剪力墙及框架柱的轴压比,得到了轴压比对结构体系抗震性能的影响,同时试验过程清楚地表明了外围框架结构在高层混合结构抗震体系中的作用。2.柔度法在处理梁、柱构件力–变形曲线下降段时会引发数值计算上的问题,无法得到正确的解答。本文透彻分析了导致问题发生的数学原因,提出了新的解决方法。新方法能够很好的处理力–变形曲线的下降段,弥补了已有解决方法存在的不足之处。3.用数学力学方法证明了传统的多垂直杆单元模型是一种建立在Timoshenko梁理论基础上的应用于剪力墙非线性分析的单元模型,系统分析了多垂直杆单元模型的力学性质,将其和连续弹性体的梁单元有机的联系在一起,改变了该单元模型自被提出以来力学性质认识不够透彻的现状。分析了单元模型中一个重要参数C值的含义,指出了调节C值的作用。然后在Euler-Bernoulli梁理论的基础上创建了一种新的多垂直杆单元模型,新模型比原有模型计算精度更高,计算速度也更快。比较了两种常见的剪力墙非线性单元模型,分层壳单元模型和多垂直杆单元模型,在理论基础上的异同,通过算例对比,指出了两种单元在不同条件下应用上的差别。4.根据框筒结构的受力特点,创建了一个框筒结构简化非线性分析单元模型,该模型建立在将框筒结构连续化处理的基础上,可以考虑结构中出现的剪力滞现象。简化模型能够节省大量的计算时间,可用于初步设计中,然后对这种简化处理手法向实腹筒体拓展进行了讨论。5.利用本文所提出的计算模型对文中高层混合结构层模型低周反复加载试验和一个15层钢框架–混凝土核心筒混合结构1/10缩尺模型的拟动力试验进行了数值模拟。模拟的结果表明,本文提出的高层混合结构非线性分析计算模型能够取得不错的精度,可以满足结构设计的需要,但仍存在一些问题有待今后的研究解决。更多还原

【Abstract】 Tall building hybrid structures (TBHS), which are composed with steel frame and concrete core-tubes (shear-walls) or with composite steel frames and concrete core-tubes (shear-walls), become fast developing structure system of the tall buildings in China. They make full use of the respective advantage of the steel and concrete. The seismic response of the TBHS is an important criterion to decide whether such structure system should be widely popularized. To restrict the response of the structure in the elastic stage through structure design is not economic, so the seismic response of the TBHS is the hot spot for the scholars in recent years. The seismic performance of the storey model of the TBHS is researched through the low reversed cyclic loading test. Based on the existing research results, the study on the dynamic elasto-plastic analysis of the TBHS is improved and the nonlinear model of member, the algorithm of the member and structures and the simple analysis methods of some structures are discussed in this dissertation. The following aspects are mainly discussed:1. Six different types of the storey model of TBHS are researched through low reversed cyclic loading test and the hysteretic curves of each specimen are obtained. It can be concluded that the seismic performance of the steel frame-shear wall structure and steel composite frame-shear wall structure is better than that of the reinforcement concrete frame-shear wall structure from the curves. The influence of the axial compression ratio on the seismic performance of the structure systems is obtained by the value of ratio. The role of the outer frame in the TBHS to resis seismic action is showed throughout the test process.2. Numercical problems will appear when dealing with the declined segment of the force-deformation curve through the flexibility method, so the correct solution can not be obtained. The reason is analyzed and the solving method is put forward. Through the new method, the declined segment of the force-deformation curve is treated well comparing to the existing method and the defects of the existing methods are remedied.3. Through the mathematical and mechanical methods, it is proved that the multi-vertical-line-element model (MVLEM) is a nonlinear element model of the shear wall which is based on the Timoshenko beam theory. The mechanical properties of the MVLEM are analyzed systemically and the model is connected to the beam element of the continuum, so the fact that the properties of MVLEM can not be understood clearly from the model is put forward is changed. The meaning of C which is an important parameter of the MVLEM is analyzed. The effects of changing the value of C are pointed out. Then, based on the Euler-Bernoulli beam theory, an improved MVLEM is created. The solution is more accurate and the calculating speed is faster by adopting the new model. The differences between the two popular nonlinear models of the shear wall, MVLEM and multi-layer shell model are compared in theory and in practical applications through the examples.4. A simplified nonlinear element model of frame-tube structures is established. The model is based on the equivalent membranes analogy and the shear lag effect can be considered. Adopting the simplified model, the amount of calculation is greatly reduced and the model is suitable for quick evaluations of frame-tube structures in nonlinear analysis during the preliminary design stage. Then, the extension of such processing method to the tube structures is discussed.5. The dynamic elasto-plastic analysis are carried out on the low reversed cyclic loading test of the storey model of TBHS and a pseudo-dynamic experimental research of a 1/10 scale 15-storey steel-concrete hybrid structure. The results proved that the nonlinear element models of the TBHS adopted in this dissertation are validated and the demands of the structure design can be satisfied by using those models, but there are still some problems to be solved in the future.更多还原