受损钢框架结构力学性能试验研究

发布时间：2018-04-20 23:15

本文选题：钢框架结构 + 损伤　；参考：《中南林业科技大学》2017年硕士论文

【摘要】：钢结构建筑随在役时间增长、遭受环境腐蚀、自然灾害等因素影响,会发生局部损伤,从而需要对结构的安全性能进行重新评估。对于钢结构建筑而言,有些结构虽然受损,仍然能够继续使用,直接拆掉会造成极大的浪费。但损伤后的钢结构是否还能够继续满足二次使用,结构力学性能会发生怎样的改变,是当今亟待研究的问题之一。本文采用试验研究,数值分析与理论推导三者结合的方法,对受损钢框架结构力学性质进行了深入研究,其主要研究内容如下:通过材性试验得到用三折线表示的Q345钢二次加载的弹性模量随损伤程度变化的关系,并将Q235和Q345钢材的二次加载弹性模量统一用同种公式表示。用钢框架试验使框架受损并且研究损伤后框架的力学行为。试验结果表明:受损后的钢框架抗侧刚度下降;受损后的钢框架最大极限承载能力下降。采用有限元分析软件ABAQUS对损伤试验进行模拟,得到框架各处位移、应变的变化规律。在第一次加载与第二次加载过程中:将试验得到的框架柱顶水平位移值与有限元分析得到的柱顶位移值进行了对比,两者基本吻合;将试验测量与有限元分析得到的两处(框架梁左侧三分点处与右侧钢柱上端)的应变进行了对比,也大致吻合。最后在参数分析阶段,分析了不同损伤程度和不同损伤部位对钢材抗侧刚度的影响,结果表明:损伤程度越高,抗侧刚度越低;相同损伤程度下,底端受损比顶部受损对降低结构的抗侧刚度更显著。得到一种能够考虑截面损伤和残余侧移的结构计算方法并且用Fortran程序实现了理论的计算。将第一次加载与第二次加载的程序计算得到的柱顶位移与试验测得位移、有限元分析得到的位移进行了对比验证,对比结果比较吻合。最后,对8层单跨钢框架结构进行算例分析。分析结果表明:在相同加载条件下,初始残余变形越大,加载时的侧向位移值越大;残余侧移除增大受损该层弯矩以外,对于临近楼层的弯矩增加也比较大,随楼层相隔越远而增加的越少。
[Abstract]:With the increase of service time, the steel structure will suffer from environmental corrosion, natural disasters and other factors, which will lead to local damage, so it is necessary to re-evaluate the safety performance of the structure. For steel structures, although some structures are damaged, they can continue to be used, which will cause great waste. However, whether the damaged steel structure can continue to meet the secondary use, and how the mechanical properties of the structure will change, is one of the urgent problems to be studied. In this paper, the mechanical properties of damaged steel frame structures are studied by means of experimental study, numerical analysis and theoretical derivation. The main research contents are as follows: the relationship between the secondary loading modulus of Q345 steel and the damage degree of Q345 steel is obtained by the material property test, and the elastic modulus of Q235 and Q345 steels is expressed by the same formula. The frame was damaged by steel frame test and the mechanical behavior of the frame after damage was studied. The experimental results show that the lateral stiffness of the steel frame decreases after the damage, and the maximum ultimate bearing capacity of the steel frame decreases after the damage. The finite element analysis software ABAQUS is used to simulate the damage test, and the variation law of displacement and strain around the frame is obtained. In the process of the first loading and the second loading, the horizontal displacement value of the column top obtained by the test is compared with the displacement value of the column top obtained by the finite element analysis. The strain obtained from the test measurement and the finite element analysis (the third point on the left side of the frame beam and the upper end of the steel column on the right side) are compared and the results are in good agreement with each other. Finally, in the stage of parameter analysis, the effects of different damage degree and different damage location on the lateral stiffness of steel are analyzed. The results show that the higher the damage degree, the lower the anti-lateral stiffness; The damage at the bottom is more significant than that at the top in reducing the lateral stiffness of the structure. A structural calculation method which can take account of cross-section damage and residual lateral displacement is obtained and the theoretical calculation is realized by Fortran program. The column top displacement calculated by the program of the first loading and the second loading is compared with the displacement measured by the experiment and the displacement obtained by the finite element analysis is compared and verified. The results are in good agreement with those obtained by the finite element analysis. Finally, the 8-story single-span steel frame structure is analyzed as an example. The results show that under the same loading conditions, the larger the initial residual deformation is, the greater the lateral displacement is, and the larger the bending moment of the adjacent floor is, the larger the residual lateral displacement is, besides increasing the moment of the damaged layer. The further away the floors are, the less they increase.
【学位授予单位】：中南林业科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU391

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