地震模拟振动台基础动力反应的比较分析

发布时间：2018-09-17 20:09

【摘要】：结构振动台实验是结构抗震分析的主要方法之一,而结构抗震实验需要借助地震模拟振动台。在有关地震模拟振动台的问题中,其基础的动力计算是关键之一。目前,地震模拟振动台基础的动力反应分析没有规定的方法,主要参考一些基于动力机器基础计算的经验方法。苏州科技学院正拟建一座三向六自由度地震模拟振动台,台面尺寸为6m×8m,本文针对这一实际工程,对振动台基础的动力反应计算方法做了一系列的分析比较。本文在系统总结国内外动力基础分析方法的基础上,主要做了如下工作：1.参照动力机器基础的设计方法,计算了上述6×8m地震模拟振动台基础的几何参数,并据此提出了基础的初步设计方案。2.采用《动力机器基础设计规范》、拉普拉斯变换法和动力阻抗法这三种常见的频域分析方法,对该地震模拟振动台基础分别进行了动力响应计算,对比发现：由于计算过程中三种方法采用的基本参数(主要是阻尼和刚度)的求取方法不同,计算得到的加速度响应在低频区和共振区存在一定差异,在高频区趋向-致；但是,三种方法的计算结果均满足地震模拟振动台基础加速度小于0.1g这一振动控制要求。3.在大型有限元软件ABAQUS基础上,详细介绍了一种计算振动台基础动力时程响应的有限元方法,其中包括振动台基础的建模、人工边界的选取、动力加载方式等。同时,与上述三种方法的结果进行了比较,结果表明：若以最大加速度反应作为控制目标,相对于有限元结果,规范方法较保守,动力阻抗法略显不安全,拉普拉斯变换法较吻合。4.采用有限元法对地基剪切模量的灵敏度进行了分析,结果表明：地基剪切模量与振动台基础动力响应基本成线性关系。最后,对全文的研究内容进行了总结,并讨论了今后进一步的研究工作。
[Abstract]:Structural shaking table experiment is one of the main methods for seismic analysis of structures. The dynamic calculation of the foundation is one of the key problems in the seismic simulation shaking table. At present, there are no prescribed methods for dynamic response analysis of shaking table foundation in earthquake simulation, and some empirical methods based on dynamic machine foundation calculation are mainly referred to. The Suzhou Institute of Science and Technology is planning to build a seismic simulation shaking table with three directions and six degrees of freedom, the size of which is 6 m 脳 8 m. In view of this practical project, a series of analysis and comparison of the dynamic response calculation method of the vibration table foundation are made in this paper. On the basis of systematically summarizing the analysis methods of dynamic foundation at home and abroad, this paper mainly does the following work: 1. With reference to the design method of the dynamic machine foundation, the geometric parameters of the foundation of the 6 脳 8m earthquake simulation shaking table are calculated, and the preliminary design scheme of the foundation is put forward. In this paper, the dynamic response of the foundation of the earthquake simulation shaking table is calculated by using three common frequency-domain analysis methods, the Code for Design of dynamic Machine Foundation, the Laplace transform method and the dynamic Impedance method. It is found that the calculated acceleration response is different in the low frequency region and the resonance region because of the difference of the basic parameters (mainly damping and stiffness) in the calculation process, and the acceleration response is trend-induced in the high frequency region. However, the calculated results of the three methods can meet the vibration control requirement of the vibration control of the shaking table foundation acceleration less than 0.1 g. Based on the large-scale finite element software ABAQUS, a finite element method for calculating the dynamic time-history response of shaking table foundation is introduced in detail, including the modeling of shaking table foundation, the selection of artificial boundary, the dynamic loading mode and so on. At the same time, compared with the results of the above three methods, the results show that if the maximum acceleration response is taken as the control target, the code method is more conservative than the finite element method, and the dynamic impedance method is slightly unsafe. The Laplace transformation method is in good agreement with .4. The sensitivity of the foundation shear modulus is analyzed by the finite element method. The results show that there is a linear relationship between the foundation shear modulus and the dynamic response of the shaking table foundation. Finally, the research content of this paper is summarized, and further research work is discussed 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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