水下不规则网状空间钢结构弹塑性动力时程分析

发布时间：2019-02-13 03:18

【摘要】：随着我国改革开放和整个国民经济形势的蓬勃发展,空间结构像雨后春笋般发展壮大。各类建筑雄伟的矗立在各大中城市,形成了地区的标志,大多数都体现了空间结构的优势。在让人们感受现代文明的同时,也反映出我国建筑科学技术进入了可以与国际实力相抗衡的新时代。但是目前结构的弹塑性分析大多是针对多、高层建筑,对于水下不规则空间结构的研究还相对较少。本文采用弹塑性动力时程分析法计算水下不规则网状空间钢结构在罕遇地震作用下的反应,根据所得的计算结果,对于该结构在罕遇地震时的抗震性能研究及考虑水体因素的影响具有一定的理论意义和参考价值。具体过程如下:(1)介绍空间钢管结构基本特点及相关概念,阐述了抗震相关分析理论发展过程及研究历史与现状。(2)介绍了动力弹塑性时程分析的理论基础、动力平衡方程及相关的数值算法;阐述了本文按目标反应谱选取地震波的方法。(3)利用有限元软件SAP2000建立了弹塑性分析模型。按目标反应谱进行选波的方法,选取了2组天然地震波及1组人工地震波,根据三维三向地震波激励的输入原则设置了12种工况,并进行了在罕遇地震作用下的弹塑性动力时程分析。结果表明,结构的整体刚度较大,在9度罕遇地震作用下最大位移值小于位移限值。结构出现的塑性铰较少,主要分布在相对较薄弱的中心圆环处,少数构件出现轻微损坏。结构达到预定的抗震性能目标,具有良好的抗震能力。(4)考虑水体阻尼对结构地震反应的影响,通过不同阻尼比值的模型在罕遇地震下所得结果的对比,得出水下结构的动力分析中建议考虑水体阻尼的影响;然后采用Housner简化模型与附加质量模型进行对比分析,得出水体晃动对结构水平方向起到了一定的减震效果。
[Abstract]:With the rapid development of China's reform and opening-up and the whole national economy, the spatial structure has sprung up. All kinds of buildings stand majestically in large and medium cities, forming regional symbols, most of which embody the advantages of spatial structure. While making people feel modern civilization, it also reflects that Chinese architectural science and technology has entered a new era that can compete with international strength. But at present, the elastoplastic analysis of structures is mostly aimed at many tall buildings, and the research on underwater irregular space structures is relatively rare. In this paper, elastoplastic dynamic time-history analysis method is used to calculate the response of steel structures with irregular underwater reticular space under rare earthquake. It has certain theoretical significance and reference value for studying the seismic behavior of the structure under rare earthquake and considering the influence of water body factors. The specific processes are as follows: (1) the basic characteristics and related concepts of spatial steel tube structure are introduced, the development process of seismic correlation analysis theory and the history and present situation of seismic correlation analysis are described. (2) the theoretical basis of dynamic elastic-plastic time-history analysis is introduced. Dynamic equilibrium equation and related numerical algorithm; In this paper, the method of selecting seismic waves according to the target response spectrum is described. (3) the elastic-plastic analysis model is established by using the finite element software SAP2000. According to the method of target response spectrum, two groups of natural earthquakes and one group of artificial seismic waves are selected, and 12 working conditions are set according to the input principle of three-dimensional three-direction seismic wave excitation. The elastoplastic dynamic time history analysis under rare earthquake is also carried out. The results show that the overall stiffness of the structure is large and the maximum displacement value is less than the displacement limit value under the action of 9 degrees rare earthquake. The plastic hinge of the structure is less, mainly distributed in the relatively weak central ring, and a few members appear slight damage. The structure achieves the target of seismic performance and has good seismic capability. (4) considering the influence of water damping on the seismic response of the structure, the comparison of the results obtained under rare earthquakes is made by the models of different damping ratios. It is concluded that the influence of water damping should be considered in the dynamic analysis of underwater structures. Then the Housner simplified model and the additional mass model are compared and analyzed, and it is concluded that the sloshing of the water body plays a certain damping effect on the horizontal direction of the structure.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU391;TU352.11

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