两阶段工作软钢消能器力学性能理论及试验研究

发布时间：2018-03-05 14:31

本文选题：软钢消能器　切入点：两阶段工作　出处：《东南大学》2015年硕士论文　论文类型：学位论文

【摘要】：软钢消能器作为被动减震领域的一种耗能装置,因其滞回性能良好、安装更换方便等优点,被广泛地应用到建筑结构减震设计中。近年来,国内外学者研究开发了形式多样的软钢消能器,但是他们大多耗能形式单一,无法同时兼顾小震和大震作用。本文基于已有的研究成果,将面外弯曲屈服和面内剪切屈服两种不同的耗能机理有机的结合起来,提出一种弯剪组合型软钢消能器,以实现消能器的两阶段屈服耗能目标。面外弯曲型软钢消能器相对于面内剪切型具有更大的屈服位移,基于这一理论基础,通过合理设计弯曲板和剪切板的尺寸和用钢材料,可以实现耗能装置的两阶段工作目标,本文首先对组成耗能装置的剪切板和弯曲板分别开展了力学性能理论研究,推导了剪切板与弯曲板核心性能参数的理论计算公式。基于单板模型的理论分析,通过有限元分析软件试算确定弯曲板和剪切板的合理尺寸,并对设计的弯剪组合型软钢消能器建立准确的边界条件,进行单调加载和往复加载数值模拟分析,研究其应力发展状态,得出弯剪组合型软钢消能器的第一屈服位移、第二屈服位移、滞回曲线、骨架曲线等参数,以便设计试验构件并与试验结果进行对比。针对所设计的耗能装置开展试验研究,首先对Q235钢材和低屈服点钢材进行了材料性能试验,得到了两种钢材弹性模量、屈服强度、极限强度、伸长率的等核心参数,确定材料的本构关系。其次,对4个不同参数的弯剪组合型软钢消能器进行了低周往复加载试验,并分析其荷载位移曲线及应变发展趋势,结果表明弯剪组合型软钢消能器的滞回曲线饱满,耗能能力稳定,与有限元计算结果对比发现,两者在滞回曲线、骨架曲线等方面吻合较好,证明采用有限元软件对弯剪组合型软钢消能器进行模拟分析结果可信,同时也证明了该型消能器核心性能参数理论公式的实际可行性。利用有限元软件ANSYS对弯剪组合型软钢消能器进行参数化分析,分别建立了100个剪切板和80个弯曲板单板模型,考察剪切板和弯曲板厚度、宽度及高度对其性能的影响,并确定了各自屈服位移和屈服后刚度的经验公式,提出弯剪组合型软钢消能器的三折线恢复力模型,并给出了模型核心参数的计算公式。根据弯剪组合型软钢消能器的两阶段工作机理,提出了其不同于传统软钢消能器的工程设计方法,并通过有限元软件SAP2000和MIDAS Gen对设置了弯剪组合型软钢消能器的减震结构进行多遇地震及罕遇地震作用下的动力时程分析。结果表明,弯剪组合型软钢消能器能够很好的实现两阶段耗能目标,有效消耗大震和小震输入结构的能量。
[Abstract]:As a kind of energy dissipation device in the field of passive shock absorption, mild steel dissipator has been widely used in the design of structural shock absorption in recent years because of its good hysteretic performance and convenient installation and replacement. Domestic and foreign scholars have studied and developed a variety of mild steel energy dissipators, but most of them have a single form of energy dissipation, which can not take into account the action of small earthquakes and large earthquakes at the same time. By combining the two different energy dissipation mechanisms of out-of-plane bending yield and in-plane shear yield, an energy dissipator composed of bending and shearing is proposed. In order to achieve the two-stage yield energy dissipation target of the energy dissipator, the out-of-plane flexural mild steel dissipator has a larger yield displacement than the in-plane shear type. Based on this theoretical basis, the dimensions of the bending plate and the shear plate and the steel material are reasonably designed. The two-stage work goal of energy dissipation device can be realized. In this paper, the mechanical properties of shear plate and bending plate, which constitute the energy dissipation device, are studied respectively. Based on the theoretical analysis of the single plate model, the reasonable dimensions of the bending and shearing plates are determined by the finite element analysis software. The boundary conditions of the designed flexible steel dissipator are established, and the monotone and reciprocating loading numerical simulation analysis are carried out. The stress development state is studied, and the first yield displacement of the bending-shear composite mild steel dissipator is obtained. The second yield displacement, hysteretic curve, skeleton curve and other parameters can be used to design test components and compare with the test results. First, the material properties of Q235 steel and low yield point steel are tested, and the core parameters of elastic modulus, yield strength, ultimate strength and elongation of two kinds of steels are obtained, and the constitutive relation of the material is determined. In this paper, the low cycle reciprocating loading tests of four flexural shear combined type mild steel dissipators are carried out, and the load-displacement curve and strain development trend are analyzed. The results show that the hysteretic curve of the combined bending and shear type mild steel dissipators is full and the energy dissipation capacity is stable. Comparing with the results of finite element calculation, it is found that the hysteretic curves and skeleton curves are in good agreement with each other. It is proved that the simulation results of bending and shear composite type soft steel dissipators with finite element software are credible. At the same time, it is proved that the theoretical formula of core performance parameters of this type of energy dissipation device is feasible. By using the finite element software ANSYS, the parametric analysis of bending and shear composite type soft steel dissipator is carried out, and the 100 shear plates and 80 bending plate veneer models are established, respectively. The effects of the thickness, width and height of shear plate and bending plate on their performance are investigated. The empirical formulas of yield displacement and post-yield stiffness are determined, and the triple-line restoring force model of bending shear combined type mild steel energy dissipator is proposed. The calculation formula of the core parameters of the model is given. According to the two-stage working mechanism of the flexible steel dissipator, the engineering design method, which is different from the traditional soft steel dissipator, is put forward. The dynamic time history of the structure with flexible steel dissipator is analyzed by finite element software SAP2000 and MIDAS Gen under the action of frequent and rare earthquakes. The results show that, The bending-shear combined type mild steel energy dissipator can achieve the two-stage energy dissipation target effectively consuming the energy of the input structure of large earthquake and small earthquake.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU352.1

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