哑铃形钢管混凝土构件压弯试验研究及刚度和承载力分析

发布时间：2018-03-23 23:02

本文选题：哑铃形　切入点：钢管混凝土　出处：《福建农林大学》2017年硕士论文

【摘要】：哑铃形钢管混凝土拱肋在工程实践中得到大量运用,哑铃形钢管混凝土拱肋拱桥占钢管混凝土拱桥比例高达四成之多。因而,对哑铃形钢管混凝土的力学性能进行深入的研究具有重要的工程意义。目前,与哑铃形截面钢管混凝土构件相关的试验研究相对较少,已进行的有哑铃形钢管混凝土轴压、纯弯、偏压试验,关于哑铃形截面钢管混凝土构件的压弯试验还未开展。另外,关于钢管混凝土的研究多集中在极限承载力方面,刚度方面的研究较少。在工程设计方面,除了对构件进行承载能力极限状态设计外,还需进行正常使用极限状态设计。因此,哑铃形钢管混凝土在压弯状态下外部荷加对刚度承载力影响的研究显得尤为迫切。本文通过试验,研究和分析压弯复合作用下不同轴压比对哑铃形钢管混凝土抗弯承载力和抗弯刚度两个方面影响,具体工作如下:(1)综述整理国内外圆(方)钢管混凝土抗弯刚度和压弯承载力相关曲线相关试验和理论研究现状;(2)结合现有试验资料和条件,进行压弯试验方案设计,进行4根不同轴压比的哑铃形钢管混凝土构件压弯复合试验;(3)对比4根哑铃形钢管混凝土构件压弯复合作用下的试验结果,分析轴压比(n)对构件抗弯刚度、抗弯承载力的影响。试验结果表明:当轴压比较小时(0～0.35)初始抗弯刚度和抗弯承载力随轴压比增大而增大,但当轴压比超过0.35时,初始抗弯刚度和抗弯承载力随轴压比增大而减小;(4)将试验所得的不同轴压比影响下的哑铃形钢管混凝土构件抗弯刚度、压弯承载力相关曲线和已有规范、文献的计算结果进行对比。对比发现:现有规范的抗弯刚度公式计算结果比试验值偏大,而N-M相关曲线方程式计算结果相比试验结果偏小。
[Abstract]:The dumbbell concrete filled steel tube arch rib is widely used in engineering practice, and the proportion of dumbbell shaped concrete filled steel tube arch rib arch bridge is as high as 40% of the steel tube concrete arch bridge. It is of great engineering significance to study the mechanical properties of concrete filled dumbbell shaped steel tube (CFST). At present, there are few experimental studies related to the concrete filled steel tube members with dumbbell section, and the axial compression of concrete filled dumbbell steel tube (CFST) has been carried out. In addition, the research on concrete-filled steel tube (CFST) is mainly focused on ultimate bearing capacity, but less on stiffness. In engineering design, the research on concrete filled steel tube (CFST) with dumbbell section has not been carried out. In addition to carrying out load-carrying capacity limit state design, it is also necessary to carry out the normal use limit state design. It is particularly urgent to study the effect of external loading on stiffness bearing capacity of concrete filled dumbbell steel tube under compression and bending conditions. The influence of different axial compression ratio on flexural bearing capacity and flexural stiffness of concrete filled dumbbell steel tube is studied and analyzed. The specific work is as follows: (1) summarizing and sorting out the relevant tests and theoretical studies on the curves related to the bending stiffness and compressive and bending capacity of concrete-filled steel tubular (CFST) at home and abroad. (2) combining with the existing test data and conditions, the design of the test scheme for compression and bending is carried out. Four concrete filled dumbbell concrete filled steel tube members with different axial compression ratios were subjected to compression and bending tests. The results were compared with those of four dumbbell shaped concrete filled steel tube members under compression and bending conditions. The flexural stiffness of the concrete filled steel tube members under axial compression ratio was analyzed. The experimental results show that the initial bending stiffness and flexural capacity increase with the increase of axial compression ratio, but when the axial compression ratio exceeds 0.35, the initial flexural stiffness and flexural capacity increase with the axial compression ratio increasing, but when the axial compression ratio exceeds 0.35, the initial bending stiffness and the flexural bearing capacity increase with the increase of axial compression ratio. The initial flexural stiffness and flexural bearing capacity decrease with the increase of axial compression ratio. It is found that the calculated results of the existing formulas for bending stiffness are larger than the experimental values, while the results of the N-M correlation curve equations are smaller than the experimental results.
【学位授予单位】：福建农林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U441

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