不同Rayleigh阻尼取值的土层地震反应分析的比较研究

发布时间：2018-05-09 02:00

本文选题：滞回阻尼 + 等效线性化　；参考：《苏州科技学院》2013年硕士论文

【摘要】：土层地震反应分析是确定地表地震动参数的一个重要环节,是地震工程学中一个重要的研究课题。常用的土层线性地震反应分析方法是等效线性化频域分析方法和时域逐步积分方法。时、频域两种方法的唯一差别是阻尼的选取,而阻尼差异的根本原因在于求解Rayleigh阻尼系数时所选取的频率(本文称之为目标频率)的不同。本文比较了不同目标频率下的不同Rayleigh阻尼取值的时、频域计算结果的差异,从而为工程实际应用中目标频率的选取提供参考。主要工作总结如下：1.编制了一维时域土层线性地震反应分析程序,从而可以进行不同Rayleigh阻尼系数取值的土层地震反应数值模拟。2.采用一维土层模型,比较了7种不同Rayleigh阻尼取值的时域分析方法与频域分析方法的土层地震响应计算结果,结果表明：影响阻尼系数的不同目标频率的选取是时域计算结果异同的主要原因；采用完整Rayleigh阻尼公式且目标频率采用土层的第一和第三阶自振频率时能取得与频域结果较为一致的结果。3.基于抗震规范中的场地特征周期,并结合大多数多、高层建筑结构基本自振周期经验公式,提出了时域分析中确定完整Rayleigh阻尼公式中的目标频率的一种新方法,即取两个目标频率分别为1/(5Tg)和1/Tg,其中Tg为场地特征周期。通过实例计算表明,此方法与采用第一和第三阶自振频率的计算结果、以及与频域计算结果相吻合,但该方法应用起来更加简单、方便。最后,对本文的研究工作进行了总结,指出了今后有待于进一步研究的问题。
[Abstract]:Soil seismic response analysis is an important part of determining ground motion parameters and an important research topic in seismic engineering. The methods of linear seismic response analysis of soil layer are equivalent linearization frequency domain analysis method and time domain stepwise integral method. The only difference between the two methods in frequency domain is the selection of damping, and the fundamental reason of damping difference lies in the difference of the frequency chosen in solving the damping coefficient of Rayleigh (referred to as the target frequency in this paper). In this paper, the difference of frequency domain calculation results of different Rayleigh damping values under different target frequencies is compared, which provides a reference for the selection of target frequencies in engineering practice. The main work is summarized as follows: 1. A one-dimensional time-domain linear seismic response analysis program is developed to simulate the seismic response of soil layers with different Rayleigh damping coefficients. Using one-dimensional soil model, the seismic response of soil layer calculated by seven different Rayleigh damping methods in time domain and frequency domain are compared. The results show that the selection of different target frequencies affecting damping coefficient is the main reason for the difference and similarities of the results in time domain. Using the complete Rayleigh damping formula and the target frequency using the first and third order natural frequencies of the soil layer, the results. 3 are in good agreement with the results in the frequency domain. Based on the site characteristic periods in the seismic code and the empirical formula for the basic natural vibration period of high-rise building structures, a new method for determining the target frequency of the complete Rayleigh damping formula in time domain analysis is proposed. The two target frequencies are 1 / 5 Tg) and 1 / 1 Tg respectively, where TG is the characteristic period of the site. Examples show that the method is in agreement with the first and third order natural frequencies and the results in frequency domain. However, the method is simpler and more convenient to be applied. Finally, this paper summarizes the research work and points out the problems to be further studied in the future.
【学位授予单位】：苏州科技学院
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU435

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