超弹性SMA减震结构随机振动理论研究

发布时间：2018-03-13 00:29

本文选题：SMA　切入点：阻尼器　出处：《河北工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：超弹性形状记忆合金(Shape Memory Alloy,简称为SMA)具有大变形恢复功能,且抗腐蚀、抗疲劳性好,是实现结构被动控制的理想材料。目前关于超弹性SMA对结构振动控制的研究多是在确定性地震激励下进行的,而地震动是一随机过程,因此研究SMA减震结构的随机振动将更具有工程意义。本文围绕SMA阻尼器控制结构的随机振动展开理论研究,主要内容如下:1、设计了耗能复位型SMA阻尼器和复位型SMA阻尼器,介绍了其构造和工作原理。在SMA的Graesser本构模型基础上,建立了两种SMA阻尼器的力学模型,进而提出了各自的简化力学模型。2、介绍了随机过程基本理论以及几种典型的地震动平稳随机模型。假定地震地面运动是具有平稳过滤白噪声随机过程,给出了与《建筑抗震设计规范》(GB50011-2010)相对应的随机地震动模型参数。3、将地震动视为平稳过滤白噪声随机过程,分别针对耗能复位型SMA阻尼器和复位型SMA阻尼器,采用随机等价线性化法建立了减震结构的随机运动方程,再将其表达为随机状态方程,进而推导了减震结构的随机状态反应公式;基于结构最大层间位移的首次超越破坏准则和多自由度串联可靠度模型,研究了多自由度线性结构的动力可靠性。4、分别计算了耗能复位型SMA阻尼器和复位型SMA阻尼器对一6层钢框架结构的随机振动控制,结果表明:两种阻尼器均能有效抑制结构的随机地震反应(层间位移标准差、层间速度标准差和最大层间位移),大大提高结构的动力可靠性。5、以一12层框架结构为例,以结构各层层间位移方差和最小为目标函数,采用遗传算法分别对耗能复位型SMA阻尼器和复位型SMA阻尼器在结构上的布置进行了优化。优化结果与其他阻尼器位置工况的计算结果进行了比较,证明了遗传算法的可靠性,并指出:在阻尼器数量相同条件下,将阻尼器布置在结构的中下层,将具有更好的减震效果。
[Abstract]:Shape Memory alloy (Sima) has large deformation recovery function, corrosion resistance and fatigue resistance. It is an ideal material to realize the passive control of structures. At present, most of the studies on the vibration control of structures by superelastic SMA are carried out under deterministic earthquake excitation, and the ground motion is a stochastic process. Therefore, it will be of engineering significance to study the random vibration of SMA dampers. In this paper, the theoretical research on the random vibration of SMA dampers is carried out. The main contents are as follows: 1. The energy dissipation reset SMA dampers and the reset SMA dampers are designed. Based on the Graesser constitutive model of SMA, two kinds of mechanical models of SMA damper are established. Furthermore, the simplified mechanics models. 2, the basic theory of stochastic process and several typical stationary random models of ground motion are introduced. The ground motion of earthquake is assumed to be a stochastic process with stationary filtered white noise. The parameters of random ground motion model corresponding to the Code for Seismic Design of buildings (GB50011-2010) are given. The ground motion is regarded as a stationary filtered white noise random process, and the energy dissipation SMA dampers and reset SMA dampers are respectively used. The stochastic equation of motion is established by using the method of stochastic equivalent linearization, and then expressed as the equation of random state, and then the formula of stochastic state response of the structure is deduced. Based on the first transcendental failure criterion of the maximum interstory displacement of the structure and the series reliability model of multiple degrees of freedom, The dynamic reliability of linear structures with multiple degrees of freedom (MDOF) is studied. The stochastic vibration control of a six-story steel frame structure with energy dissipation reset SMA dampers and reset SMA dampers is calculated respectively. The results show that both kinds of dampers can effectively suppress the random seismic response of the structure (the standard deviation of interstory displacement, the standard deviation of interstory velocity and the maximum displacement between layers), and greatly improve the dynamic reliability of the structure .5. take a 12-story frame structure as an example. Taking the variance sum of displacement between layers as the objective function, The genetic algorithm is used to optimize the structural layout of the energy dissipation reset SMA damper and the reset SMA damper respectively. The optimization results are compared with the calculated results of other dampers, and the reliability of the genetic algorithm is proved. It is pointed out that when the number of dampers is the same, the dampers will be arranged in the middle and lower layers of the structure, which will have better seismic absorption effect.
【学位授予单位】：河北工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU352.1

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