考虑初应力的组合层状周期性基础动力特性分析

发布时间：2018-10-31 20:39

【摘要】：摘要：周期结构具有频率衰减域特性,在衰减域所包含的频率范围内,波的传播将被抑制,层状周期性隔震基础方面的已有成果也证明了这一点。然而,在实际工程中,基础承受着来自上部结构的重力,该重力将转化为基础的初应力,初应力对周期性基础衰减域特性的影响目前尚未被研究者考虑。本论文将在考虑初应力的前提下,研究层状周期性基础衰减域的计算方法,并用有限元软件ANSYS,对组合层状周期性基础的动力特性进行模拟分析。主要研究内容及所取得的成果如下： 1、详细介绍了传递矩阵法,并利用该方法对含有初应力的层状周期性基础进行了衰减域计算。 2、选用混凝土和橡胶作为层状周期性基础的组成材料进行衰减域计算,分析了几何参数和初应力值对层状周期性基础的影响,并设计了两种层状周期性基础模型。 3、建立了组合层状周期性基础模型,并用有限元软件ANSYS进行了频率响应分析,结果表明,与不施加初应力的周期性基础相比,施加初应力的组合层状周期性基础不仅可以拓宽衰减域,而且更加有效地降低低频波对结构的影响。 4、对周期性基础进行有限元动力响应分析,发现初应力的施加可以有效地减小框架结构顶点的加速度、位移及层间位移响应。除此之外,通过位移时间历程分析,进一步验证了衰减域的存在对隔震所起的作用。 5、在组合层状周期性基础上施加初应力,并研究其在Big Bear地震波作用下的响应。结果表明,该基础具有非常明显的隔震作用。
[Abstract]:Absrtact: periodic structure has the characteristic of frequency attenuation domain, and the wave propagation will be restrained in the frequency range contained in the attenuation domain, which has been proved by the existing achievements in layered periodic isolation foundation. However, in practical engineering, the foundation bears the gravity from the superstructure, which will be converted into the initial stress of the foundation. The influence of the initial stress on the characteristics of the attenuation domain of the periodic foundation has not been considered by the researchers. On the premise of considering the initial stress, this paper will study the calculation method of the attenuation domain of the layered periodic foundation, and use the finite element software ANSYS, to simulate and analyze the dynamic characteristics of the composite layered periodic foundation. The main research contents and achievements are as follows: 1. The transfer matrix method is introduced in detail, and the attenuation domain of layered periodic foundation with initial stress is calculated by using this method. 2. Using concrete and rubber as the material of periodic foundation, the attenuation domain is calculated, the influence of geometric parameters and initial stress on the periodic foundation is analyzed, and two kinds of periodic foundation models are designed. 3. The combined layered periodic foundation model is established, and the frequency response analysis is carried out with the finite element software ANSYS. The results show that compared with the periodic foundation without applying initial stress, The combined layered periodic foundation with initial stress can not only widen the attenuation region but also reduce the influence of low frequency wave on the structure more effectively. 4. The finite element dynamic response analysis of periodic foundation is carried out, and it is found that the application of initial stress can effectively reduce the acceleration, displacement and interstory displacement response of the frame structure. In addition, through the analysis of displacement time history, it is further verified that the existence of attenuation domain plays an important role in isolation. 5. The initial stress is applied on the basis of combined layered periodicity, and its response under the action of Big Bear seismic wave is studied. The results show that the foundation has a very obvious isolation effect.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU435

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