基于能量输入历程特征的改进往复推覆分析方法研究

发布时间：2018-02-09 17:36

本文关键词： 地震能量框架结构推覆分析耗能能力-需求曲线延性系数能量输入历程　出处：《长沙理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：Pushover分析方法作为一种静力弹塑性分析方法,由于其理论简单、操作方便并能够获得较为理想的分析结果而受到广泛的关注。通过Pushover分析方法设计人员可以获得结构在水平力作用下所产生的一批塑性铰的位置以及产生塑性铰的顺序和范围,从而使设计人员从更加微观的角度了解结构的破坏过程,这样有利于设计人员作出更加合理的设计方案,同时与动力时程分析相比Pushover分析方法的计算量大为缩减,因此其不仅具有很高的理论价值而且在实际工程应用方面也受到广大设计人员的青睐。然而传统的Pushover分析方法也存在一些不足之处。首先其只注重了结构的侧向变形而忽略了地震持时、地震能量输入特征等因素的影响,其次它所采用的单向加载模式忽略了结构在地震中的累积损伤效应,并且不同的水平力分布模式甚至不同方向的加载都会对计算结果产生很大的影响。因此本文针对Pushover分析方法的不足之处,将结构的耗能特征参数与Pushover分析方法相结合,进行了以下研究:1)提出了基于能量的结构延性需求估算方法,即通过单向Pushover分析得到结构的单向耗能能力曲线,通过估算结构的变形能得到其单向耗能需求曲线,并将耗能能力曲线与耗能需求曲线绘制于同一坐标系下,通过两条曲线的交点获得结构的延性需求;2)在此基础上,通过讨论延性系数对能量耗散历程的影响,提出了通过延性系数估算结构能量输入历程参数的方法;3)基于延性需求与结构能量输入历程参数估算方法,提出了基于变形能输入历程特征的改进往复推覆分析方法。从而在考虑变形的基础上兼顾考虑了地震持时和地震能量输入历程特征对结构损伤的影响。基于上述方法,采用有限元分析软件OpenSees对一个3层3跨RC框架和一个6层3跨RC框架进行自适应往复推覆分析,并将结构的最大层间位移角、累积滞回耗能及其分布、瞬时变形能输入历程等反应指标与动力时程分析结果进行对比的,验证了该改进方法的适用性。
[Abstract]:As a static elastic-plastic analysis method, Pushover analysis method is simple in theory. It is easy to operate and can obtain more ideal analytical results and has attracted wide attention. Through Pushover analysis method, designers can obtain the position of a batch of plastic hinges produced by the structure under horizontal force, as well as the order and scope of producing plastic hinges. In order to make the designer understand the damage process of the structure from a more microscopic angle, it is helpful for the designer to make a more reasonable design plan, and at the same time, compared with the dynamic time history analysis, the calculation of the Pushover analysis method is greatly reduced. Therefore, it is not only of high theoretical value but also favored by many designers in practical engineering application. However, the traditional Pushover analysis method also has some shortcomings. Firstly, it only pays attention to the lateral direction of the structure. The deformation ignores the earthquake duration, The characteristics of earthquake energy input and other factors affect it. Secondly, the unidirectional loading mode it adopts ignores the cumulative damage effect of structure in earthquake. And different horizontal force distribution modes and even different directions of loading will have a great impact on the calculation results. Therefore, in this paper, the energy dissipation characteristic parameters of the structure are combined with the Pushover analysis method in view of the shortcomings of the Pushover analysis method. The following studies are carried out: (1) an energy-based method is proposed to estimate the ductility demand of a structure, that is, the one-way energy dissipation curve of the structure is obtained by unidirectional Pushover analysis, and the one-way energy demand curve is obtained by estimating the deformation energy of the structure. The energy dissipation capacity curve and the energy demand curve are drawn in the same coordinate system. The ductility demand of the structure is obtained by the intersection of the two curves. On this basis, the influence of the ductility coefficient on the energy dissipation history is discussed. The method of estimating structural energy input history parameters by ductility coefficient is presented. The method is based on ductility demand and structural energy input history parameter estimation. An improved reciprocating and push-over analysis method based on the characteristics of the input history of deformation energy is proposed, which takes into account the influence of seismic duration and energy input history characteristics on the damage of the structure on the basis of considering the deformation. A 3-story 3-span RC frame and a 6-story 3-span RC frame are analyzed by the finite element analysis software OpenSees. The maximum interstory displacement angle, cumulative hysteretic energy dissipation and its distribution are analyzed. The applicability of the improved method is verified by comparing the transient deformation energy input history with the results of dynamic time history analysis.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU313

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