圆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：2018-03-15 12:54

本文选题：钢管混凝土　切入点：抗弯刚度　出处：《福建农林大学》2017年硕士论文　论文类型：学位论文

【摘要】：钢管混凝土作为组合结构承受荷载作用,具有承载能力高、施工速度快,在地震作用下构件延性较好等优点,已被广泛应用于现代工程结构中。目前,国内外关于钢管混凝土结构的研究成果较多,但是相比钢管混凝土压弯构件受力性能研究,大部分学者注重偏压状态下的力学性能分析,并且这类研究主要集中于钢管混凝土复杂受力下的承载力分析,对复杂受力下的刚度变化研究较少。随着经济发展,结构的跨度不断增大以及建筑物形式日趋复杂,研究钢管混凝土构件在不同参数下的刚度和承载力变的尤为重要。本课题针对圆钢管混凝土构件,对其压弯力学性能进行了试验研究,具体内容如下:1、参考国内外钢管混凝土相关文献,总结圆钢管混凝土压弯方面的研究成果,确定了圆钢管混凝土构件在压弯受力下的力学性能试验方案。2、进行了 4根圆钢管混凝土构件的试验研究,试验以轴压比为主要参数,重点考察了不同轴压比(0、0.10、0.31、0.45)对圆钢管混凝土试件抗弯刚度和承载力的影响。结果表明:适当轴压比(0～0.31)能提高试件的抗弯刚度和抗弯承载力,但当轴压比较大(0.45)时,试件的抗弯刚度和抗弯承载力均出现了下降段,区别在于抗弯刚度下降幅度较小,而抗弯承载力则下降明显。3、根据试验过程中的M-φ曲线,在相关理论分析的基础上,将5部国外规范以及2部国内规范中关于弹性阶段抗弯刚度(初始阶段和使用阶段)的计算值与试验值进行了对比,基于试验结果对不同规范的计算方法提出合理化建议。4、利用我国现行《钢管混凝土结构技术规程》(DBJ/T13-51-2010)、《钢管混凝土结构设计与施工规范》(CECS 28-2012)和《钢管混凝土结构技术规范》(GB 50936-2014)中钢管混凝土构件压弯承载力的设计方法与本文试验结果进行对比。结果表明:GB 50936-2014中建议的圆钢管混凝土 N-M相关曲线的设计方法可较好对本次试件的承载力进行计算,另外规程CECS 28-2012中关于钢管混凝土 N-M相关曲线计算方法可在工程中要求预留较大安全冗余的情况下应用于实际设计。
[Abstract]:Concrete filled steel tube (CFST), as a composite structure, has been widely used in modern engineering structures because of its high bearing capacity, fast construction speed and good ductility under earthquake. At present, concrete filled steel tube (CFST) has been widely used in modern engineering structures. There are many researches on concrete-filled steel tubular structure at home and abroad, but compared with the research on the mechanical behavior of concrete-filled steel tubular members, most of the scholars pay attention to the mechanical performance analysis under the state of partial compression. And this kind of research mainly focuses on the bearing capacity analysis of concrete-filled steel tube under the complex force, but the research on the stiffness change under the complex force is less. With the development of economy, the span of the structure is increasing and the form of the building is becoming more and more complex. It is very important to study the stiffness and bearing capacity of concrete-filled steel tubular members under different parameters. The specific contents are as follows: 1. Referring to the relevant literature on concrete-filled steel tube at home and abroad, we summarize the research results on the compression and bending of concrete-filled circular steel tube. The test scheme of mechanical properties of concrete-filled steel tubular members under compression and bending loading was determined. The experimental study of four concrete filled circular steel tube members was carried out. The axial compression ratio was taken as the main parameter in the test. The effect of different axial compression ratio (0. 10 ~ 0. 31 ~ 0. 45) on the flexural stiffness and bearing capacity of concrete filled circular steel tube specimens is investigated. The results show that the appropriate axial compression ratio of 0 ~ 0. 31) can improve the bending stiffness and bearing capacity of the specimens, but when the axial compression ratio is larger than 0. 45), The bending stiffness and the flexural bearing capacity of the specimen both appear a descending section, the difference is that the bending stiffness decreases slightly, while the flexural bearing capacity decreases obviously .3.According to the M- 蠁 curve in the course of the test, based on the relevant theoretical analysis, The calculated values of flexural stiffness in elastic stage (initial stage and use stage) in five foreign codes and two domestic codes are compared with the experimental values. Based on the test results, some reasonable suggestions are put forward for the calculation methods of different codes. 4. Using the current Technical regulations for Concrete-filled Steel Tubular structures in China, DBJ / T13-51-2010, CECS28-2012) and concrete filled Steel Tubular structure Technology. The design method of compressive and bending bearing capacity of concrete-filled steel tubular members is compared with the test results in this paper. The results show that the design method of N-M correlation curve of concrete filled circular steel tube suggested in GB 50936-2014 is better for this specimen. The bearing capacity is calculated, In addition, the calculation method of N-M correlation curve of concrete-filled steel tube in CECS 28-2012 code can be applied to practical design under the condition that large safety redundancy is required in engineering.
【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】：TU398.9

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