【作者】 杨成；

【导师】 赵人达；

【作者基本信息】 西南交通大学 ， 结构工程， 2010， 博士

【摘要】 要在实际工程中有效实现基于性能的抗震设计(简称PBSD)思想,需要有高效的结构分析方法为基础,这种方法既要对结构易损性有一个相对简洁直观的分析,同时要尽可能地保持力学分析精度,而现有分析手段对这两方面的兼顾程度还不甚理想。例如能力谱作为结构易损性评价的重要依据,通常用静力推覆分析(简称SPO)计算得出,其计算过程和时程分析之间存在分析机理上的本质差异,这严重制约了SPO结果的工程实用性；而离散、单一的弹塑性时程分析又无法针对变化的地震作用水准描述结构全过程的非线性行为,不同地震动输入的分析结果间也缺乏比较基准。因此,未来的性能化设计必须结合传统易损性评估手段简洁直观的特点,以及复杂动力响应计算精度上的优势,提炼出更合理的分析流程。从现有的研究趋势上看,如何将真实动力响应分析和传统PBSD分析方法有效结合,是实现上述目标的关键。本文从对传统易损性评估手段基于动力学因素的改进应用,和利用时程分析形成新的分析手段两方面入手展开工作,所取得的成果将对PBSD研究有所帮助,其具体内容概括如下：首先,回顾了性能化抗震设计在行业规范和工程研究领域的发展现状。针对其未来发展的三个特点以及现阶段存在的不足,建议在现行基于性能的抗震设计方法中更加充分地考虑结构动力响应特性。其次,总结了现有的自适应SPO分析流程,根据结构等效阻尼比和振型滑移规律,提出在侧向力模态合并过程中考虑振型耦合效应。改进前后的对比表明：考虑了水平侧向力模式耦合的自适应SPO对结构非线性行为的预测在趋势上更为接近时程分析结果,能够在一定程度上弥补对工程需求参数(简称EDP)的估计不足。再次,从结构易损性评估和地震动破坏势综合评价两方面作用介绍了增量动力分析(简称IDA)的基本概念和研究现状。针对IDA实际应用中的具体问题进行了研究。基于程序接口技术提出了可以捆绑时程分析程序的IDA主程序编制方法；并以典型RC框架结构为例,进行了结构局部损伤和整体抗震性能基于IDA的评估,其主要内容包括：①由于针对每条记录的每个放大级别都需要进行PGA调幅、时程分析计算启动、计算结果搜集整理三样工作,因此当分析记录和IDA放大级数达到一定数量时,人工反复执行上述工作显得非常繁琐,本文给出了详细的IDA捆绑电算分析流程,可将上述工作通过主程序一次启动全部完成,为IDA的工程实用化从计算技术上提供了借鉴。②通过算例分析对比了SPO和IDA曲线分析结果间的固有差异,并指出这种差异随结构具体形式和EDP的不同而不同。③利用IDA数据插值方法对比了时程分析和SPO间进行结构罕遇地震分析的结果差异,并指出利用IDA数据插值有利于以不同的EDP为基准进行上述两种方法间的比较。④针对离散的时程分析结果数据在坐标中的分布特点,给出了利用分位曲线评价IDA数据的分析流程,比较了两种不同IDA分位曲线绘制方法间的异同点。最后,开展了对不同地震动样本形成的IDA曲线差异机制的研究；对多样本IDA曲线的收敛改进进行了探讨,主要内容包括：①利用结构等效单质点IDA曲线分析,基于IDA曲线屈服后分岔现象,初步展示了地震动特征对结构非线性响应的影响机理。②提出了在不同地震作用下,基于统一结构关键损伤指标的非线性发展分布比较方法,分析了在不同地震作用和不同的动力非线性发展阶段,结构体系损伤的变化分布规律。③针对损伤结构等效周期Tf和振型滑移指数α的取值方法,提出了基于Cordova双参数IM函数的改进公式,IDA曲线收敛效果得到了进一步提高。更多还原

【Abstract】 Current PBSD methods still lack efficiently tools and analysis procedure to show real structural dynamic behavior, which can’t be expressed enough by SPO. Inherent difference between capacity curves and real structural nonlinear developing characters based on dynamic responses can not been eliminated at all. Demand diagram can’t give the details of structural system. So it is very important to put more dynamics factors on current PBSD analysis tools or straightly putting forward efficient procedures into seismic performance evaluation and design. All the work is helpful for the accuracy and applicability of PBSD. The thesis’work concentrates on improving the current SPO and IDA procedure for better considering dynamics behaviors, the summarization as follows:The first, PBSD and PBEE’s development in structural codes and engineering research is summarized. For its three properties and deficiencies, the opinion is proposed that more dynamic factors should be considered in current PBSD or PBEE analysis tools.The second, based on the current adaptive SPO lateral forces combined by multiple lateral force modes, the coupling lateral force modes during pushover analysis is proposed because of the equivalent damp ratio and period shift. The results from cases analysis shows that using coupling lateral force modes by CQC is more accurate than by SRSS, results from the improved method is more like that of nonlinear RHA. The difference between the SPO and CQC in the weak storey can be reduced in greatest degree.The third, the method of wrapping RHA programs is proposed, including the cases analysis for detecting local damage and evaluating structural seismic performance. The main point including:①the computer analysis procedure for IDA is given in detail. The technology of wrapping RHA is realized by using DFPORT function, which is provided by C++or Fortran, and finish the work of the RHA program’s being started up and the data’s being collected and rewritten multiply.②Inherent difference in the results of SPO and IDA is compared,③method of interpolation based on IDA data is applied in comparing the maximum DM data under ultimate stage of IDA and SPO.④the procedure of evaluating IDA results by fractile is given,and the difference methods is analyzed, by which the fractiles are calculated from DM to IM, or from DM to IM.At last, some work concentrates on the technology of summarizing different IDA curves, which are resulted by the diversity of seismic records. The improved method of summarizing IDA curves is proposed.①The fork after yielding of elasto-plastic SDOF’s IDA curves shows that the characters of seismic records will affect the plastic joints’nonlinear developing path based on the maximum dynamic responses. All that forms the new explanations for the discreteness of IDA curves and RHA results.②the method for comparing structural damage distribution along the nonlinear developments is proposed, which is based on the same key damage index. New method will produce more reasonable evaluation results about structural seismic performance.③Based on the two parameter intensity measure propose by Cordova, The improvement on calculating equivalent damage structure’s period Tf and period shifting factor a produces better results of summarization for IDA curves.更多还原