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框架结构基于能量的试验和抗震设计方法研究

Research on Experiment and Seismic Design Mothedology of RC Frame Structure Base on Energy

【作者】 何利

【导师】 叶献国;

【作者基本信息】 合肥工业大学 , 结构工程, 2011, 博士

【摘要】 尽管基于能量方法从20世纪中期提出至今已取得较大研究进展,但仍有不少问题尚待解决。本文以能量分析为主线,对钢筋混凝土构件耗能能力进行了试验研究;比较了目前主要的损伤指数模型;验证了三维弹塑性结构分析程序CANNY的适用性和准确性;分析了阻尼对地震能量反应的影响;根据选择的188条地震水平向加速度时程记录,建立了一种基于复合强度指标的弹性和弹塑性输入能量谱,在此基础上建议了滞回耗能比值谱;分析了地震输入能量竖向分布规律;探讨了一种将输入能需求转化为弹性等效加速度需求的设计方法。经过研究得出了以下成果与结论:(1)进行了8个来自实际工程的框架柱试件的低周反复加载试验,利用试验数据研究了构件的耗能能力,对损伤指数模型进行了比较研究,提出了使用建议。(2)利用构件层次、结构层次的实际试验结果和实际工程案例对三维结构有限元分析软件CANNY进行了验证,认为CANNY是目前较好的适合能量分析用软件。(3)对粘滞阻尼和复阻尼、阻尼比的取值等内容进行了介绍,对不同阻尼模型对框架结构地震反应进行了研究,并提出了使用建议。(4)基于文献研究了主要的输入地震动参数,包括地震动幅值、频谱、持时以及复合性的地震动参数。认为基于能量的设计方法必须同时考虑幅值、频谱和持时的因素。按照我国的场地分类,从PEER数据库中选择了188条记录建立了基于复合强度指标的弹性输入能量谱。(5)按四类场地各选12条地面运动记录,共计48条,进行了统计分析,建立了SDOF体系的弹塑性输入能量谱。该谱将地面运动参数和结构动力参数紧密地结合起来了,为方便于设计应用,提出了经过二次拟合的基于阻尼、强度折减系数和周期的计算公式。在此基础上建立了滞回耗能比值谱。(6)进行了MDOF体系输入能分解为SDOF体系输入能的数值验证研究。研究了滞回耗能的层间分布,得出结论:滞回耗能的层间分配,即不是梯形分布也不是对数正态分布,基本无法提炼出具有实用价值的公式。(7)根据按我国场地分类规则建立的输入能量谱,基于能量需求,并将这种需求转化为考虑了延性的等效加速度需求,提出了直接基于能量的设计方法。

【Abstract】 Although a lot of advancement has been achieved since energy-based methods were presentedin1950s, many issues on energy are worth for further study. Based on the energy concept, anexperimental research was conducted on the energy dissipation capacity of reinforced concretecolumn specimens, and the main damage index models were compared according to the test data. Inthe paper, the elastic-plastic three-dimensional structure analysis program CANNY applicabilitywas verified, and the influence of damping on energy reaction were analyzed.Through inputting of188seismic records according to the site classification of Chinese seismic code, the three-segmentelastic input energy spectra and then an elastic-plastic input energy spectra are proposed based on thecompound intensity indicator. On this basis, a method to evaluate theE h/EIratio is proposed.Vertical distribution of seismic input energy is analyzed, and a design method of changing the inputenergy demand into the equivalent acceleration demand is proposed. The following findings andconclusions are reached:(1) Eight specimens of reinforced concrete columns under cyclic loading were conducted. Onthis basis, damage index model for comparative study were conducted, and the use of suggestionsare proposed.(2)The three-dimensional structure analysis program CANNY was verified by using the actualtest data and the actual works of component-level and structural level, and the CANNY is shown agood energy analysis software.(3) The viscous damping and complex damping, the measured damping ratio data and analysis,etc. were introduced according to the research results in the literatures. The influence of differentdamping models on seismic response of frame structure has been studied, and proposals are putforward.(4) Describes the main input ground motion parameters, including ground motion amplitude,frequency characteristics, duration and the composite ground motion parameters. This paper arguesthat energy-based design methodology must also consider the factors of the magnitude, frequencycharacteristics and duration. Through inputting of188seismic records according to the siteclassification of Chinese seismic code, three-segment elastic energy spectra are proposed based onnormalization methods.(5) A statistical analysis is conducted on the48records belong to the four sites, respectively.The elastic-plastic SDOF system input energy spectra are proposed based on the compoundintensity indicator, and fitting formulas are put forward for the convenience of the designapplication. On this basis, a method to evaluate theE h/EIratio is proposed. (6) Confirmation study on the decomposition of the input energy of elastic MDOF system to theinput energy of elastic SDOF system is conducted. Vertical distribution of the hysteretic energy isanalyzed. The study shows that the vertical distribution of the hysteretic energy is not trapezoidaland lognormal distribution, and a practical formula can not be extracted from.(7) A design method of changing the input energy demand into the equivalent accelerationdemand is proposed, and the China’s establishment of site classification rules and the ductility orstrength reduction factor of structures are taken into account in the method.

  • 【分类号】TU323.5;TU352.11
  • 【被引频次】3
  • 【下载频次】409
  • 攻读期成果
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