【作者】 王文武；

【导师】 李慧；

【作者基本信息】 兰州理工大学 ， 结构工程， 2006， 硕士

【摘要】 由于现代建筑结构的造型、布局形式的多变,结构的质量中心和刚度中心往往不重合,因此在地震作用下结构除发生平动外,还会产生平—扭耦联的扭转反应。理论分析与震害现象表明结构的扭转反应会加速偏心结构在地震作用下的破坏,在某些情况下甚至成为导致结构破坏的主要因素,因此引起了国内外学者的极大关注,并对此做了很多研究及探索。围绕这一问题,本文对隔震层为非线性的偏心隔震结构的结构响应进行了研究。 将结构看成串并联质点体系,用双线性刚度模型描述隔震层的非线性刚度,利用Matlab编制计算程序,分别对偏心隔震结构、偏心非隔震结构及非偏心非隔震结构进行了时程分析,并比较了三种结构动力响应的差异。 介绍了一种适合随机分析的非线性等效线性化方法,并用此方法对隔震支座的非线性刚度进行了等效线性化。将地震动加速度过程模拟成过滤白噪声模型(本文采用的是Kanai-Tajimi修正模型),利用等效线性刚度,应用虚拟激励法对非线性偏心隔震结构进行了随机分析,计算了结构响应的统计特征,并与偏心非隔震结构及非偏心非隔震结构的动力响应作了比较。 时程分析和随机分析的计算结果表明偏心会使结构基本周期减小,地震响应增大,并且地震的作用越大偏心引起的耦联响应越大。采用基础隔震可以减小结构的响应,而且对偏心结构的扭转效应同样具有消减作用,并且地震响应越大消减的幅度也越大。就减震效果来说,与非偏心结构相比,偏心结构的减震的效果有所下降。更多还原

【Abstract】 Due to the various styles of modeling and overall arrangement of building structures, the mass centre of the structure and rigidity centre is always not coincident, so the translation-torsion coupling response may be induced under earthquake excitation by reason of structural eccentricities. Theory analysis and seismic disaster has shown that torsional response results in rapid destruction. In some cases, it even becomes the main factor causing the structural failure, so many researchers have focused increasing attention and efforts to this problem and significant progress has been made in this field. With regard to this point, the study on structural response of eccentric base-isolated structure is presented in this paper.The particle of structure is regarded as the series-parallel system, and the non-linear stiffness of the isolation layer is described as the bilinear model. Matlab software is adopted to compile the calculation program, through which, response of the eccentric structure, symmetry structure and eccentric isolated structure is analyzed with the time-process method separately, and then the dynamic response of the structures mentioned above is under comparison.This paper also presents an equivalent linearization method, which is available for random analyses and can be used to obtain the equivalent stiffness of isolation bearing. By simulating ground acceleration as filtering white noise excitation and using the equivalent stiffness, random analysis of non-linear eccentric isolated structure is performed through pseudo excitation method. The statistic characteristic of structural response is calculated to compare with that of non-isolated structures.The results of both time-process and random analysis show that the effect of eccentricity will reduce the dominant period and magnitude the dynamic response of the structure. Base isolation system can suppress the structural response as well as the torsional effect of eccentric isolated structure. Compared with symmetry structure, seismic mitigation extent of eccentric structure descends slightly.更多还原