【作者】 郭辉；

【导师】 王社良；

【作者基本信息】 西安建筑科技大学 ， 结构工程， 2007， 硕士

【摘要】 为了使建筑结构在地震灾害作用下能够维持所需要的性能水平，抗震规范已经提高了对结构弹塑性变形验算的要求。结构的弹塑性变形计算可采用静力弹塑性分析方法予以简化，其中应用较多的是Pushover分析方法和能力谱方法。但是由于结构弹塑性变形计算的复杂性，Pushover方法和能力谱方法目前均存在一些问题需要解决，因此本文对Pushover分析方法进行了改进，并对能力谱法方法中相应的问题提出了一些建议。本文首先论述了静力弹塑性方法在国内外的发展及其研究与应用现状，介绍了Pushover分析方法、能力谱方法、位移影响系数法和N2方法等几种有代表性的分析方法，着重讨论了Pushover分析方法和ATC-40能力谱方法的基本思想和基本原理，指出了在求结构能力谱过程中存在的三个问题，即：如何考虑高振型的影响、采用何种侧向力分布形式及怎样确定目标位移等问题。为了解决上述问题，本文提出了基于振型参与重量来确定起主要影响的振型数，以考虑高振型对结构性能的影响，并对目前常用的几种侧向力加载方式进行了分析，结果表明对于高层建筑结构，按模态加载所得结果要优于其他加载形式的结果。接着，讨论了模态Pushover法(MPA)的步骤及假定，指出其所作假定对结构屈服后的刚度变化考虑不足等问题，并通过对振型向量的选取进行了改进，提出了两阶段的侧向力加载模式，同时对确定结构目标位移的方法也作了改进。随后，论文应用文中提出的改进静力弹塑性分析方法，通过SAP2000有限元分析软件，对一15层钢筋混凝土框架结构计算模型进行了静力弹塑性分析，并与动力时程分析结果进行了比较，验证了本文所提方法的可靠性和适用性。结果表明，采用本文改进的静力弹塑性分析方法对结构进行推覆分析，能够比较准确地模拟结构的地震反应，具有易操作和计算精度高等优点。最后，本文还对应用静力弹塑性分析方法计算不规则结构和考虑二次效应等方面存在的问题进行了探讨。更多还原

【Abstract】 In order to design such a structure that it is capable of sustaining the behavior required when subjected to various earthquake actions, the code for seismic design of buildings has improved the requirement for checking calculation of elastic-plastic deformation; the calculation of elastic-plastic deformation for structures can be simplified through the static elastic-plastic analysis, in which the more widely used are the Pushover analysis method and the capacity spectrum method. However, owing to the complexity of the calculation of elastic-plastic deformation for structures, some problems required to be pressingly solved exist at present in the Pushover analysis method and the capacity spectrum method, so with respect to the Pushover analysis method, this article made some modifications and put forward several suggestions for problems present in the capacity spectrum method.Firstly, in this paper the development of static elastic-plastic analysis method and the present situation of domestic-overseas researches of this method were discussed; several representative analysis methods were introduced, such as the Pushover analysis method, the capacity spectrum method, the influencing coefficient method of displacement, and N2 method, etc; the fundamental concepts and principles of the Pushover analysis and ATC-40 capacity spectrum method were emphatically dealt with; three existing problems were pointed out during solving process of the capacity spectrum for structures: how to consider the influence of high order modal, which pattern of lateral load should be selected, and how to determine target displacement, etc. For the sake of solution of problems described above, this paper addressed the numbers of modal which play an essential influence on the seismic response and then can be determined on the basis of modal participation weight, so as to consider the influence of high order modal on structural performance; Besides, this paper performed an analysis on several lateral load patterns which are commonly employed at present, and the results indicated that the results obtained by modal load are superior to those by other load patterns. Subsequently, the procedures and assumptions of modal Pushover analysis (MPA) were explored, and such problems were pointed out as the deficiency in considering rigidity variation of structures after yield due to those assumptions; the selection of modal vector was modified, and the lateral load pattern of two phases was advanced; meanwhile, the methods for determination of target displacement were also revised. Next, this paper utilized the modified elastic-plastic analysis method proposed here, through finite element software SAP2000, performed a static elastic-plastic analysis on the calculation model for a 15-story RC frame structure, and compared the analysis results with results obtained by dynamic time history analysis, which verified reliability and applicability of the method presented in this paper. The research results revealed that the adoption of static elastic-plastic analysis method in this paper to conduct a Pushover analysis on structures can comparatively simulate structural response to earthquake, and it possesses desirable advantages of easy operation and high-accuracy calculation, etc. Finally, the application of the static elastic-plastic analysis method in irregular structures and the second order effect on structures were investigated.更多还原