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1.
半刚性连接钢管混凝土框架剪力墙结构的动力特性分析 总被引：1，自引：1，他引：1
将钢管混凝土框架剪力墙结构作为连续弹性无限自由度结构，建立自由振动方程，分析了半刚性连接对结构自振周期和频率的影响，推导出半刚性连接框剪结构自振周期系数的计算公式。使用通用有限元程序ANSYS进行结构的模态分析，有限元分析结果和公式计算结果吻合良好。结果表明，半刚性连接使得结构自振周期增大，半刚性连接对高阶振型自振周期的影响很小。提出了地震区钢管混凝土框剪结构体系的设计建议，可供工程设计人员参考使用。 相似文献
2.
高层建筑振动周期计算是，高层建筑结构抗震设计的主要计算内容之一，文中论述了高层建筑结构振动周期计算的可靠性，并用具体数值算例研究了计算模型和结构参数随机变化高层建筑振动周期计算可靠性和频谱变化的影响。 相似文献
3.
建立了北京盆地含起伏地形的地下介质三维速度结构模型, 以有限差分方法对盆地内的3次地震动进行了数值模拟． 计算了地表加速度反应谱, 论证了反应谱的有效周期范围, 从而获得了盆地结构对长周期段反应谱的平均放大系数, 并对不同周期时反应谱的平均放大系数进行了分区, 为今后城市的合理规划和长周期建筑物的建设提供了抗震设防参考． 最后对反应谱平均放大系数与等效沉积物厚度之间的关系进行了回归, 得出了反应谱放大系数随沉积物厚度增大而增强, 以及随周期增大而减弱等结论． 相似文献
4.
性能化抗震是工程抗震研究的重要方向。根据位移性能水准，计算不同周期结构达到性能水准时所需输入的最大地震动加速度值，建立性态谱；基于性态谱，研究自振周期、恢复力模型和第二刚度折减系数等特征参数对性态谱的影响。研究表明:性态谱表征了周期、性能水准和地震需求的三维谱关系，可预测达到不同性能水准时结构的地震需求；结构自振周期和第二刚度折减系数在短周期段对性态谱有显著影响，随结构自振周期的增大，谱值差别减小；双线型恢复力模型是否退化影响达到相同变形目标时的地震需求，退化模型性态谱谱值小于非退化模型。 相似文献
5.
考虑剪切变形的框架结构动力分析的动态有限元法 总被引：3，自引：0，他引：3
陈淮 《地震工程与工程振动》1994,14(2):102-113
在本文中，作者提出了一种可以考虑梁单元剪切变形和转动惯量影响的框架结构动力分析的动态有限元方法。文中阐述了框架结构有限单元各阶动约束函数的概念，并用它组成结构有限单元各阶动态形函数矩阵。文中还说明了使用递推方法计算结构的各阶动特性以及利用动态有限无法求解框架结构动态响应和动应力的方法。 相似文献
6.
目前地电磁辐射的点域或有限多点频观测方法存在的事件漏测和测量结果缺乏精细度等问题，而宽频带快速时域采样又会带来数据存贮容量，数据处理和管理以及系统成本等一系列问题，针对这种情况，为克服点频测量的局限性，研究了一种与信号相位无关的正交锁定频域采样的地电磁辐射谱观测方法，并给出了相应的系统硬件实现结构，这种方法在一次地电磁辐射过程中谱特性不变或某一谱分量持续时间不小于扫描周期的情况下，能准确地测量信号 相似文献
7.
多点输入的相邻结构—地基—土地震反应分析 总被引：5，自引：0，他引：5
本文采用样条函烽与半解析函数耦合法分析水平方向无限延伸的地基上，并对基岩处采用多点输入地震动的相邻结构－地基－土系统进行了分析，避免了人为的有限边界处理和有限边界地震动的处理，通过算例，得到了相邻结构－地基－土相互作用一些有意义的规律。 相似文献
8.
有限持时的实例提示我们结构的最大位移可能出现时滞现象,且工程结构的自振周期与出现结构最大位移的时间密切相关,特别在长周期结构中,位移主要受瞬态振动的控制。本文通过小波分解、振幅调整、线性叠加3步骤实现了地震动瞬态反应与稳态反应的分离,通过小波分量瞬态反应与反应谱研究,证实了长周期结构的最大位移不仅可能发生在共振情况下,也可能发生在外载激励已经消失,但结构的瞬态振动仍有较大余幅的情况下。瞬态振动对长周期结构位移反应的影响与持时呈密切的关系。 相似文献
9.
《地震工程与工程振动》2016,(5)
建筑结构基本周期是结构设计所需的一项重要参数,经验公式是获得结构基本周期的主要方式之一。世界各国抗震设计规范中基本都存在结构基本周期计算公式的相关内容,且大部分规范都给出了不同结构的基本周期经验公式。由于发展背景的差异,不同国家存在着不同的结构基本周期经验公式。为充分对比国内外高层建筑结构基本周期经验公式的差异、找出我国规范中相关公式的不足之处,首先分析了我国历届规范中高层建筑结构基本周期经验公式的演变过程,并搜集了国外部分国家和地区的相关公式;然后对比分析了国内外经典经验公式的形成过程、不同之处;最后展望了我国相关规范中经验公式的未来发展方向和修订建议。 相似文献
10.
建筑物和构筑物的震害预测与建 (构 )筑物的自振周期和场地土的卓越周期之间关系密切。对某些类型建筑物振动周期的确定前人已作了很多研究。 对于复杂系统和独特的高耸建筑物 (如烟囱 )的动力特性 ,已知的确定自振周期的建筑力学传统方法并不适用 ,但至今又没有研究出精确的计算分析方法 ,对此类构筑物的分析只能借助计算机采用近似数值法进行。寻求烟囱这种弯曲模型的频率是一个变分问题 ,这一问题是基于能量的观点采用有限单元 ( МКЭ)方法解决的。但因为数值方法的结果的可靠性取决于有限单元的离散化程度 ,这种情况下须将系统分为数… 相似文献
11.
Mario de Stefano Edoardo Michele Marino Pier Paolo Rossi 《Bulletin of Earthquake Engineering》2006,4(1):23-42
In past years, seismic response of asymmetric structures has been frequently analysed by means of single-storey models, because
of their simplicity and low computational cost. However, it is widely believed that use of more realistic multi-storey models
is needed in order to investigate effects of some system characteristics (such as overstrength, higher modes of vibration,
etc.) that make behaviour of multi-storey schemes different from that of single-storey systems. This paper examines effects
of the overstrength in element cross-sections on the seismic behaviour of multi-storey asymmetric buildings. It is shown that
in actual buildings this characteristic, which is sometimes very variable both in plan and along the height of the building,
may lead to distributions of ductility demands different from those expected according to the results from single-storey models.
Consequently, torsional provisions, which aim at reducing ductility demands of single-storey asymmetric systems to those of
the corresponding torsionally balanced systems, should be re-checked in light of the behaviour of realistic multi-storey buildings. 相似文献
12.
This paper attempts to study the response of light equipment items attached to a multi-storey building that may be subjected to large torsional deformations during the earthquake excitation. To account for the effect of torsion and translation, each storey of the building is modelled as two degrees of freedom (DOFs), with one DOF for translation and the other for torsion. Perturbation techniques are employed to find closed-form expressions for the modal properties of the combined system in terms of the properties of the individual subsystems. The interaction between the equipment and building is studied for both tuned and detuned modes of vibration. Modal synthesis results obtained using the present technique based on the complete quadratic combination (CQC) method are compared with solutions obtained by other methods. 相似文献
13.
地震引起的相邻建筑物间的碰撞过去多次强烈地震中出现,并造成了较为严重的结构破坏。为研究此问题,设计建造了两座缩尺钢质模型来模拟香港两座相邻的21层建筑,对其进行了一系列振动台碰撞试验,试验结果表明复杂结构间的碰撞可能是周期性的、群周期性的或混沌的,这主要取决于间距、结构参数以及地震动参数。碰撞引起的能量传递可能对较柔较轻的邻近建筑造成较严重的地震反应和破坏。 相似文献
14.
地铁以其快捷、准时、运量大等优点,已成为重要的轨道交通形式,但由此引起的环境振动问题日益突出。针对杭州市地铁3号线曲线地段的某中学建设工程,利用有限元软件ABAQUS,对车辆-普通整体道床轨道系统的竖向耦合模型进行振动响应分析,得到考虑轨道高低不平顺影响的轨道振动源强。应用有限元软件MIDAS GTS/NX,建立双孔平行曲线盾构隧道-土-桩-建筑物系统的三维有限元模型。以轨道支点力作为激励对地铁列车运行时的隧道-土-桩-建筑物系统的振动响应进行计算,研究地铁振动波在地层中的传播规律和建筑物的动力响应特性。根据相关环境振动控制标准对建筑物的振动舒适性进行评价。结果表明：轨道加速度和扣件动支点力的最大值分别约为40 m/s2和30 kN;地层和建筑物的振动以竖向为主,水平Y向振动略大于水平X向振动;地面加速度随着距隧道中心线距离的增加而逐渐衰减;各建筑物楼层的振动主频位于16~40 Hz;部分建筑物楼层的振动响应水平已超出了规范的限值要求,建议对地铁轨道或建筑物采取适当的减振措施。 相似文献
15.
This paper proposes an aseismic design concept in which the superstructure of a base-isolated building is divided into several segments. Each segment may comprise a few storeys and is interconnected by additional vibrational isolation systems. The dynamic characteristics of the segmental buildings are investigated. The optimum parameters of the vibration isolation systems are determined by minimizing the mean square acceleration response. The seismic response of a typical segmental building subjected to the N—S component of the 1940 El Centro earthquake input is evaluated and compared with the responses of the corresponding fixed-base and conventional base-isolated buildings. The comparisons show that, when the superstructure is segmented, while the acceleration response in the superstructure remains as small as that in the conventional base-isolated building, the displacement across the base isolation system at foundation level is substantially reduced. 相似文献
16.
17.
An effective procedure is summarized without derivation for estimating the maximum response of a class of torsionally-coupled, multi-storey buildings due to earthquake ground motion characterized by response spectra. The analysis procedure is shown to be efficient and to provide insight into torsional coupling effects because the maximum response of such a torsionally-coupled, N-storey building in its njth mode of vibration is determined exactly by analysing (i) the response in the jth vibration mode (j = 1,2, N) of the corresponding torsionally-uncoupled, N-storey system; and (ii) the response in the nth vibration mode (n = 1, 2 for a one-way symmetric plan) of an associated torsionally-coupled, one-storey system. It is also demonstrated that an earlier, simpler approach in which the total (considering all vibration modes) response of the building is determined from the total response of the two simpler systems is strictly valid only under restrictive conditions, which are identified, but the simpler approach leads to results that are accurate to a useful degree. 相似文献
18.
Dougla S. A. Foutch 《地震工程与结构动力学》1978,6(3):265-294
The Ralph M. Parsons World Headquarters building, a twelve-storey steel frame structure, was subjected to a series of forced vibration tests. The natural frequencies, three-dimensional mode shapes and damping coefficients of nine modes of vibration were determined. Other features of this investigation included the study of non-linearities associated with increasing levels of response, detailed measurements of the deformation of the first floor and the ground surrounding the structure, and measurements of strain in one of the columns of the structure during forced excitation. The dynamic characteristics of the building determined by these tests are compared to those predicted by a finite element model of the structure. The properties of primarily translational modes are predicted reasonably well, but adequate prediction of torsional motions is not obtained. The comparison between measured and predicted strains suggests that estimates of stress determined from finite element analyses of buildings might be within 25 per cent of those experienced by the structure for a known excitation. 相似文献
19.
多层混凝土小型空心砌块与煤矸石页岩多孔砖组合砌体模型楼动力性能实测与分析 总被引：2，自引：0，他引：2
对一个1：1比例的多层混凝土小型空心砌块与煤矸石页岩多孔砖组合砌体模型的抗震性能进行了试验研究。对该足尺试件在抗震性能试验的不同受力阶段进行了动力测试，分别得到了结构处于弹性、开裂、屈服和破坏状态下的频率、振型、阻尼等动力参数，分析了模型动力特性的变化特点及原因，为这种结构的抗震设计及动力分析提供了依据。 相似文献