共查询到17条相似文献，搜索用时 109 毫秒
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结构平稳随机地震反应时域分析:方法 总被引：3，自引：3，他引：3
给出了三种常用的随机地震地面运动过程模型,即理想白噪声模型、金井清模型、改进金井清模型的相关函数表达式.引入状态向量,在状态空间中建立地震地面运动激励下的结构振动方程,并求解出结构的复模态特性和复模态反应.利用复模态叠加法推导出线性时不变多自由度体系在这三种随机地震动激励下的平稳协方差反应的解析式,可在时域内直接计算结构随机反应的统计特征.该方法物理概念清晰,结论简便明确,可作为实际工程结构平稳随机地震反应的实用分析方法. 相似文献
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地震工程界对随机地震动已进行了40多年的研究，提出了多种较好的随机过程模型，其中最具代表性的是日本学者金井清(Kanai)(1961)提出的过滤白噪声模型．进一步，欧进萍等(1991)在评述既往随机模型基础上，提出了地震地面运动的过滤有色噪声模型．然而，这些模型都存在一个最大的问题，就是不能合理确定模型中反映地震强度的参数————谱强度因子S0.
随机地震动研究的基础是强震记录，基于地面强震记录，人们对地震地面运动随机模型进行了大量的研究，其中对基岩地震动的模拟还有很多需要解决的问题．本文在基岩强震记录统计基础上，研究基岩地震动的随机模型和模型参数，为建立工程抗震的合理地震动模型奠定基础． 相似文献
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以平面框架结构为例阐述了结构平稳随机地震反应时域分析方法的应用。首先利用静力凝聚方法大幅度地缩减结构的自由度数目，形成一维链状模型，使得结构运动方程中只包含各层反应从而大大降低计算工作量。其次推导了结点随机反应和层间随机反应的计算公式，可以方便地获得结构在理想白噪声、金井清谱和改进金井清谱三种随机地震地面运动激励下的协方差位移反应函数和协方差速度反应函数。最后通过一个单跨双层的平面框架结构实例，阐述了这种方法的使用过程。 相似文献
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选择金井清过滤白噪声模型,采用留数定理推导出K-T谱激励的自相关函数表达式,并在此基础上利用相关函数法分析出K-T谱激励下的平稳反应,并采用功率谱方法加以验证。这些结果可为结构随机地震反应时域分析和抗震可靠性评估提供基础。 相似文献
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基于随机地震动模型的结构随机地震反应谱及其应用 总被引：13，自引：5，他引：13
本文考虑给定地震烈度下地震地面运动的随机过程性，得强震记录统计确定的地震持时和我国地震规范采用的地震地面最大加速度平均值，确定了平稳过滤有色噪声地震动模型的参数；通过大量计算和回归分析，得到了单质点振子均方地震位移的实用计算公式，提出了随机地震反应谱，等效随机地震静荷载及结构地震随机反应和可靠性分析的实用方法，把结构在随机地震动作用下的动力可靠性分析转化成了结构在等效随机地震静荷载作用下的静力可靠 相似文献
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应用随机过程的正交展开方法,将地震动加速度过程展开为标准正交基函数与标准正交随机变量的线性组合形式。在此基础上采用随机函数的思想,将正交展开式中的标准正交随机变量表达为基本随机变量的函数形式,从而实现用一个基本随机变量来表达原地震动过程的目的。结合地震动过程的正交展开 随机函数模型与概率密度演化方法,对某大型渡槽结构进行随机地震反应分析与抗震可靠度计算;重点研究空槽和三槽有水等四种工况下渡槽结构控制点位移以及控制截面内力的随机地震反应与可靠度,进而获得渡槽结构控制点和控制截面的地震反应概率信息。 相似文献
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实际记录到的真实地震动在工程结构的抗震研究、分析和设计中往往作为一种施加到结构上使结构振动，直至破坏的地震荷载．如何合理选择真实的地震动记录作为研究结构地震反应的输入，一直是国内外抗震研究和设计中引人关注的重要问题．本文首先提出了最不利设计地震动的概念；然后在收集到的国内外5000余条被认为有重要意义的地震动记录基础上，利用综合估计地震动潜在破坏势的方法，对４种场地类型分别给出了长周期、短周期和中周期结构的国内外最不利设计地震动；最后通过几类不同结构的地震反应分析，初步验证了本文所确定的最不利设计地震动的可靠性和合理性． 相似文献
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地震地面运动模型的研究 总被引：1，自引：0，他引：1
地震地面运动被模拟成均值为零的两次过滤Ｇａｕｓｓ白噪声随机过程。第一次过滤削减白噪声的高频含量;第二次过滤削减白噪声的低频含量。根据地震记录的功率谱,使用非线性函数的最小二乘法,确定了两次过滤Ｇａｕｓｓ白噪声随机过程的功率谱密度函数的参数。 相似文献
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Analysis of structural fuzzy random seismic response 总被引：2，自引：0，他引：2
Ａｎａｌｙｓｉｓｏｆｓｔｒｕｃｔｕｒａｌｆｕｚｚｙｒａｎｄｏｍｓｅｉｓｍｉｃｒｅｓｐｏｎｓｅ张跃，王光远ＹｕｅＺＨＡＮＧａｎｄＧｕａｎｇ－ＹｕａｎＷＡＮＧ１）（ＤｅｐａｒｔｍｅｎｔｏｆＣｉｖｉｌＥｎｇｉｎｅｅｒｉｎｇＴｓｉｎｇｈｕａＵｎｉｖｅｒｓｉｔ... 相似文献
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Low-frequency errors of a commonly used non-stationary stochastic model (uniformly modulated filtered white-noise model) for earthquake ground motions are investigated. It is shown both analytically and by numerical simulation that uniformly modulated filter white-noise-type models systematically overestimate the spectral response for periods longer than the effective duration of the earthquake, because of the built-in low-frequency errors in the model. The errors, which are significant for low-magnitude short-duration earthquakes, can be eliminated by using the filtered shot-noise-type models (i.e. white noise, modulated by the envelope first, and then filtered). 相似文献
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Earthquake excitation not only has evident randomness but also has strong fuzziness owing to the uncertainties in the definition of earthquake intensity and site soil classification. In this paper, the seismic ground motion is simulated as a stationary filtered white noise with fuzzy parameters, an analytical procedure is proposed to analyse the fuzzy random vibration of multi-degree-of-freedom (MDOF) hysteretic systems, and the covariance matrix of the fuzzy random responses is derived by the equivalent linearization technique. Finally, some numerical results for a two-storey shear hysteretic frame are presented to demonstrate the validity and effectiveness of the procedure proposed. 相似文献
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This paper presents a robust H∞ output feedback control approach for structural systems with uncertainties in model parameters by using available acceleration measurements and proposes conditions for the existence of such a robust ontput feedback controller.The uncertainties of structural stiffness,damping and mass parameters are assumed to be norm-bounded.The proposed control approach is formulated within the framework of linear matrix inequalities,for which existing convex optimization techniques,such as the LMI toolbox in MATLAB,can be used effectively and conveniently.To illustrate the effectiveness of the proposed robust H∞ strategy,a six-story building was subjected both to the 1940 El Centro earthquake record and to a suddenly applied Kanai-Tajimi filtered white noise random excitation.The results show that the proposed robust H∞ controller provides satisfactory results with or without variation of the structural stiffness,damping and mass parameters. 相似文献
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A method for generating a suite of synthetic ground motion time‐histories for specified earthquake and site characteristics defining a design scenario is presented. The method employs a parameterized stochastic model that is based on a modulated, filtered white‐noise process. The model parameters characterize the evolving intensity, predominant frequency, and bandwidth of the acceleration time‐history, and can be identified by matching the statistics of the model to the statistics of a target‐recorded accelerogram. Sample ‘observations’ of the parameters are obtained by fitting the model to a subset of the NGA database for far‐field strong ground motion records on firm ground. Using this sample, predictive equations are developed for the model parameters in terms of the faulting mechanism, earthquake magnitude, source‐to‐site distance, and the site shear‐wave velocity. For any specified set of these earthquake and site characteristics, sets of the model parameters are generated, which are in turn used in the stochastic model to generate the ensemble of synthetic ground motions. The resulting synthetic acceleration as well as corresponding velocity and displacement time‐histories capture the main features of real earthquake ground motions, including the intensity, duration, spectral content, and peak values. Furthermore, the statistics of their resulting elastic response spectra closely agree with both the median and the variability of response spectra of recorded ground motions, as reflected in the existing prediction equations based on the NGA database. The proposed method can be used in seismic design and analysis in conjunction with or instead of recorded ground motions. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献