T型及环口板加固T型焊接相贯圆钢管节点抗火性能研究

发布时间：2018-08-29 15:42

【摘要】：钢管结构在现代建筑当中应用广泛，钢管节点作为钢管结构中重要组成部分是设计和研究的重点。与其他形式的节点相比相贯管节点具有无需附加构件，传力路径简单、外形美观等优点。学者们对常温下相贯管节点的力学性能进行了多方面的研究。钢材的力学性能好但抗火性能差，高温下强度和弹性模量会大幅度下降。火灾是钢管结构的重要安全隐患，但是目前对钢管结构的抗火性能研究较少。本文采用试验测试和有限元分析相结合的方法对T型及环口板加固T型焊接相贯圆钢管节点的抗火性能进行了系统的研究，主要内容如下：首先对T型和环口板加固T型焊接相贯圆钢管节点进行了抗火性能试验。试验设计的两个试件除了环口板，几何尺寸和材料都一样。试验采用恒载升温的加载制度，得到了试件的升温曲线，变形曲线，破坏模式以及主管端部的应变曲线。通过试验数据的整理，对T型和环口板加固T型焊接相贯圆钢管节点的抗火性能进行了对比和分析。随后采用有限元软件ABAQUS对抗火试验进行了模拟。模型选用实体单元，采用间接热力耦合的热分析方法。有限元分析结果和试验结果的对比表明用ABAQUS进行相贯节点的抗火性能分析是可行的。然后用验证过的ABAQUS模型对未加固T型相贯圆钢管节点几何参数（D、α、β、τ、γ）、热学参数（对流系数h，辐射系数ε）以及荷载比n（临界温度和耐火极限）进行了详细的参数分析。通过参数分析确定了T型相贯节点临界温度和耐火极限参数方程的形式。然后基于大量有限元结果，利用多元非线性拟合软件Datafit进行了拟合分析，得到了T型相贯节点临界温度和耐火极限的参数方程。经检验方程是有效的，，方程计算结果与本文及其他学者的试验结果吻合良好。最后采用有限元分析法研究了环口板加固T型相贯圆钢管节点几何参数β、τ、γ、τc和ξ对节点抗火性能的影响，并与未加固T节点的抗火性能做了对比。
[Abstract]:Steel pipe structure is widely used in modern buildings. As an important part of steel pipe structure, steel pipe joint is the key point of design and research. Compared with other types of joints, intersecting tubular joints have the advantages of no additional components, simple force transfer path and beautiful appearance. The mechanical properties of intersecting tubular joints at room temperature have been studied in many aspects. The mechanical property of steel is good, but the fire resistance is poor, the strength and elastic modulus will decrease greatly at high temperature. Fire is an important hidden danger of steel pipe structure, but the fire resistance of steel tube structure is less studied at present. In this paper, the fire resistance of T-type welded circular steel pipe joints strengthened with T-shaped and annular plates is studied systematically by means of the combination of test and finite element analysis. The main contents are as follows: first, the fire resistance test of T-type welded circular steel pipe joints strengthened with T-type and annular plate is carried out. The two specimens designed are of the same geometric size and material except the annular plate. The temperature rise curve, deformation curve, failure mode and strain curve of the top end of the specimen were obtained by using the loading system of dead load. Based on the experimental data, the fire resistance of T-type welded circular steel pipe joints strengthened with annular plates is compared and analyzed. Then the finite element software ABAQUS was used to simulate the fire resistance test. The model adopts solid element and indirect thermal coupling thermal analysis method. The comparison of finite element analysis and test results shows that it is feasible to use ABAQUS to analyze the fire resistance of intersecting joints. Then the geometric parameters (D, 伪, 尾, 蟿, 纬), thermal parameters (convection coefficient h, radiation coefficient 蔚) and load ratio n (critical temperature and fire resistance limit) of unreinforced T-shaped circular steel pipe joints are analyzed by using the verified ABAQUS model. The form of critical temperature and fire resistance limit parameter equation of T type intersecting node is determined by parameter analysis. Then, based on a large number of finite element results, the parameter equations of critical temperature and fire resistance limit of T-type intersecting joints are obtained by using the multivariate nonlinear fitting software Datafit. It is proved that the equation is effective, and the calculated results are in good agreement with the experimental results of this paper and other scholars. Finally, the effects of geometric parameters 尾, 蟿, 纬, 蟿 c and 尉 on the fire resistance of T-shaped circular steel pipe joints strengthened with annular plates are studied by means of finite element analysis, and compared with those of unstrengthened T-joints.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU392.3

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