【作者】 蒋蝶；

【导师】 易伟建；

【作者基本信息】 湖南大学 ， 结构工程， 2007， 硕士

【摘要】 目前,结构抗震设计正在由传统的基于力的强度设计方法发展到基于性能或位移的延性抗震设计方法。基于性能的抗震设计作为地震工程发展的一种趋势,其基本思想将逐渐进入设计标准并应用于实际工程的设计。同时,基于性能的抗震设计是建立在可靠度理论基础上的,Pushover作为基于性能的抗震设计的一个重要手段,改进其计算精度以及对其计算结果进行概率研究是当前的研究热点。论文着重在以下几个方面进行研究工作:1.提出了基于滞回耗能的改进Pushover分析方法。将收集到的335条地震波按照场地类别等进行分组,并建立起相应的滞回耗能谱。在Chopra的多模态Pushover分析方法和Aschhein提出的基于能量的位移的基础上,利用滞回耗能谱将基于能量的位移引入到Pushover分析中,并通过自适应的水平加载方式考虑了高阶振型的影响。本文采用五分段模型来模拟框架构件受力,用Fortran90编制了基于滞回耗能、倒三角分布等五种不同加载方式的Pushover分析程序,采用SAP2000对结构进行时程分析,并通过算例验证了本文方法的可行性;2.通过基于结构体系强度失效的安全余量分析,建立Pushover分析所得的能力曲线的极限状态方程,以静力弹塑性分析得到的塑性铰出现次序作为结构主要失效模式,考虑了不同加载模式对结构体系抗力曲线随机性的影响。对抗力曲线的影响因素做敏感性因素分析,得到主要影响因素后,同时考虑结构自身以及地震作用的随机性,提出了一种计算采用基于滞回耗能的Pushover分析所得的结构体系抗力曲线保证率的方法;3.对通过敏感性分析得到的抗力曲线主要影响因素进行随机抽样,并利用所得到的结构体系极限状态方程进行直接重要抽样法,通过算例来检验本文所提方法的计算精度。结果表明:本文所提出的计算结构体系抗力曲线保证率的方法具有较高的计算精度。更多还原

【Abstract】 Presently, the seismic design has been shifted from force-based design to performance-based design or displacement-based design. As the development trend of earthquake engineering, the basic ideal of performance-based seismic design will be used as the design criterion and applied to the present projects. Meanwhile, the performance-based seismic design is based on the reliability theory. As an important tool of the performance-based design, improving the computation precision of Pushover analysis and making a probability investigation to the analysis results are the research hotspots. The research contents developed mainly in the thesis are as follows:1. The thesis put forward the adaptive hysteretic energy dissipation-based push- over analysis method. The 335 seismic waves collected are divided into groups on the basis of the field sort etc and the corresponding hysteretic energy dissipation spectra are established. Based on the modal pushover analysis given by Chopra and the energy-based drift given by Aschhein, the energy-based drift is imported into the Pushover analysis with hysteretic energy spectra, and the higher modes are taken into account with the adaptive horizontal loading pattern. In the thesis, the frame members are simulated with five subsection model. Fortran90 is used to programme for the Pushover analysis considering five different loading patterns such as hysteretic energy-based, inverted triangular distribution etc. and SAP2000 is used for the time history analysis. Lastly, two numerical examples demonstrate that the feasibility of the method in the thesis.2. With the safe margins analysis based on the intensity failure of the structural system, the limit state equation of the capacity curve from Pushover analysis is built. Taking the emergence order of plasticity ream from the static inelastic analysis as the dominant failure modes and taking account of the effects of different loading patterns on the randomicity of the capacity curve. The main affecting factors are obtained with the analysis of sensibility factors. Meanwhile, taking account of the randomicity of the structures and the earthquake action, an computing method for the guaranteed rate of the capacity curve based on the hysteretic energy-based Pushover analysis is given in the thesis.3. The random sampling is used to the main affecting factors of the capacity curve, and the direct important sampling is used to the limit state equation of the structure system. The computing precision is verified by the two numerical examples. It is concluded that the proposed method for the guaranteed rate generally has satisfactory precision.更多还原