位移系数法确定结构弹塑性目标位移的方法研究

发布时间：2019-06-22 10:14

【摘要】：目前，，随着基于性能的结构抗震设计方法应用的越来越广泛，静力弹塑性方法作为一种分析结构抗震性能的方法，逐渐得到了抗震研究者的认可。如何找到一种简便而又准确的求解结构在地震作用下的目标位移的方法，是静力弹塑性分析方法面临的关键技术难点之一。本文重点研究了位移系数法，分析各个参数的影响因素，旨在寻找到一种基于我国场地条件的位移系数求解方法。为此选取了491条地震波，并根据场地特征周期将其进行分组，通过对单自由度体系的弹塑性时程分析，统计回归了适用于我国场地条件的位移系数法公式。最后，本文设计了位于不同烈度区、不同总层数共11榀框架结构算例，利用有限元分析软件OpenSees进行弹塑性分析，对比分析改进的位移系数法和能力—需求谱法的有效性及差异，为结构目标位移的确定提供了参考建议。本文得到的主要结论如下： 1）位移系数法求解目标位移的精度取决于参数的选取，本文通过归纳分析研究，确定了适用于我国场地条件的位移系数法的求解公式；通过研究发现，系数C1主要与强度折减系数以及结构的自振周期有关，而与烈度的关联度不大。 2）对于改进的能力—需求谱法，本文对比了吕西林—周定松、范立础—卓卫东和翟长海—谢礼立模型求解钢筋混凝土结构的目标位移，三者差别不大，精度都能满足工程要求。本文算例中，对于多层框架结构，吕西林—周定松模型的精度稍高；而对于高层框架结构，范立础—卓卫东模型精度更好。 3）改进的位移系数法确定的结构目标位移较未改进的方法更接近动力时程分析结果。本文对比改进的位移系数法与改进的能力—需求谱法求解钢筋混凝土结构的目标位移，发现两者精度相差不大，但改进的位移系数法计算更为简便。
[Abstract]:At present, as the performance-based seismic design method is more and more widely used, the static elastic-plastic method, as a method to analyze the seismic performance of structures, has been gradually recognized by seismic researchers. How to find a simple and accurate method to solve the target displacement of structures under earthquake is one of the key technical difficulties faced by static elastic-plastic analysis method. In this paper, the displacement coefficient method is studied, and the influencing factors of each parameter are analyzed in order to find a method to solve the displacement coefficient based on the site conditions in our country. For this reason, 491 seismic waves are selected and grouped according to the site characteristic period. Through the elastic-plastic time history analysis of the single-degree-of-freedom system, the displacement coefficient method formula suitable for site conditions in China is statistically returned. Finally, 11 frame structures located in different intensity regions and with different total stories are designed. The elastic-plastic analysis is carried out by using the finite element analysis software OpenSees. The effectiveness and difference of the improved displacement coefficient method and the capacity-demand spectrum method are compared and analyzed, which provides a reference suggestion for the determination of the displacement of the structure target. The main conclusions of this paper are as follows: 1) the accuracy of displacement coefficient method depends on the selection of parameters. In this paper, the formula of displacement coefficient method suitable for site conditions in China is determined through induction and analysis. It is found that the coefficient C1 is mainly related to the strength reduction coefficient and the natural vibration period of the structure, but not to the intensity. 2) for the improved capability-demand spectrum method, the target displacement of reinforced concrete structures is compared with Lu Xilin-Zhou Dingsong, Fan Liji-Zhuo Weidong and Zhai Changhai-Xie Lili models. The three models have little difference and the accuracy can meet the engineering requirements. In this paper, for multi-story frame structure, the accuracy of Lu Xilin-Zhou Dingsong model is slightly higher, while for high-rise frame structure, Fan Liji-Zhuo Weidong model has better accuracy. 3) the displacement of structural target determined by the improved displacement coefficient method is closer to the result of dynamic time history analysis than that of the unimproved method. In this paper, the improved displacement coefficient method and the improved capacity-demand spectrum method are compared to solve the target displacement of reinforced concrete structures. It is found that the accuracy of the two methods is not much different, but the improved displacement coefficient method is more convenient to calculate.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU352.11;TU313

【参考文献】