圆钢管柱混凝土在焊接高温下力学性能的研究

发布时间：2018-01-08 00:08

  本文关键词：圆钢管柱混凝土在焊接高温下力学性能的研究　出处：《合肥工业大学》2017年硕士论文　论文类型：学位论文

  更多相关文章： 圆钢管混凝土柱 有限元 温度场 核心混凝土 力学性能

【摘要】：钢管混凝土柱是由钢管及其中浇筑的混凝土而形成的构件。通过钢管和混凝土之间在受力过程中的相互作用,即混凝土受到钢管的约束作用处于复杂应力状态之下,进而提高混凝土的强度,塑性和韧性性能大为改善。同时,组成钢管混凝土柱的钢管和混凝土之间具有相互贡献、协同互补、共同工作的特点,这种构件也具备较好的耐高温性能。在逆作法施工工程中,当圆钢管混凝土柱外部搭接梁时,需在圆钢管外焊接外环板用来支撑梁的内部钢筋骨架,焊接时产生的高温通过圆钢管传热到混凝土。随着温度升高,混凝土中骨料和水泥石由于发生膨胀,混凝土在圆钢管的约束作用下产生内应力,导致应力集中严重,形成微裂缝,由此降低核心混凝土的强度,对圆钢管混凝土柱的力学性能及其极限承载力产生不利影响。因此研究圆钢管混凝土柱在焊接温度场和荷载作用下力学性能的变化具有一定的工程意义。本文主要研究圆钢管混凝土柱在焊接高温下的温度场和轴向荷载作用下的应力-应变关系和构件极限承载力的研究。论文通过有限元软件ANSYS、ABAQUS对圆钢管混凝土柱外环板在焊接高温作用下的温度场分布情况进行模拟,并对圆钢管混凝土柱外环板位置在温度场基础上施加轴向荷载作用下核心混凝土力学性能进行研究。结果表明,当外环板焊接位置温度上升到约400℃时,在焊接温度场的影响下,会导致核心混凝土屈服应力降低明显,同时在施加轴向荷载时会使圆钢管柱混凝土截面承载力降低显著。论文研究的目的在于为实际工程设计和施工提供一些参考依据。
[Abstract]:Concrete-filled steel tubular column (CFST) is a member formed by steel tube and concrete-filled steel tube through the interaction between steel tube and concrete in the process of loading. That is to say, the concrete is confined by the steel tube in the state of complex stress, and then improve the strength, plasticity and toughness of the concrete. At the same time. Concrete-filled steel tube and concrete column have the characteristics of mutual contribution, cooperation and mutual work, this kind of member also has better high-temperature resistance in the reverse construction project. When the concrete filled circular steel tube column is connected with the external beam, the outer ring plate should be welded outside the circular steel tube to support the internal steel frame of the beam. The high temperature generated by welding heat transfer to concrete through the circular steel tube. With the increase of temperature. Due to the expansion of aggregate and cement stone in concrete, the internal stress of concrete is produced under the constraint of circular steel pipe, which leads to the serious stress concentration and the formation of micro-cracks, thus reducing the strength of the core concrete. The mechanical properties and ultimate bearing capacity of CFST columns are adversely affected. Therefore, it is of engineering significance to study the variation of mechanical properties of CFST columns under welding temperature field and load. In order to study the stress-strain relationship and ultimate bearing capacity of concrete-filled steel tubular columns under welding temperature and axial load, the finite element software ANSYS is used in this paper. ABAQUS is used to simulate the distribution of temperature field of circular concrete-filled steel tubular columns under welding high temperature. The mechanical properties of core concrete under axial load on the basis of temperature field are studied. The results show that when the welding temperature of outer ring plate rises to about 400 鈩，

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