火灾后中空夹层钢管混凝土构件滞回性能研究

发布时间：2018-10-20 18:49

【摘要】：由于钢管混凝土所具备的有一系列优越性,已经得到人们认可并在工程中投入使用。中空夹层钢管混凝土(CFDST)与其相比,不但具有它的优势,而且抗弯刚度更大,自重更小,在地震中结构破坏的可能性更小。然而当构件经受火灾作用后,材料的力学性能会有所改变,这可能会影响构件的抗震性能。以前国内外对此特别是火灾作用后的探索很少报道,因此详细的探索火灾后CFDST构件的滞回性能对以后土木工程领域组合结构的发展具有非凡的意义。本文具体工作如下:(1)选用ISO-834升温曲线对CFDST构件进行了火烧试验,之后对18根方形及圆形构件进行了滞回实验研究,并且以空心率、受火时间、混凝土强度、轴压比等为参数,对构件的滞回曲线、变形、刚度以及耗能能力进行了分析。(2)选用合理的热工参数和ISO-834升温曲线,利用ABAQUS对构件进行受火升温模拟,通过与实验对比确定热辐射等系数的选取,为后来与力学场模型拟合做好准备工作。(3)钢材和混凝土的性能在经受火灾作用过后会发生改变,其本构也会发生改变,在选取了合适的本构后,通过ABAQUS软件将温度场和力学场拟合在一起,将模型计算所得曲线与实验相对比,在验证模型正确的基础上,对构件的滞回曲线、变形、刚度以及耗能能力进行了分析并深入研究构件在承受低周往复荷载时内外钢管与混凝土的受力过程以及二者的相互作用力。
[Abstract]:Because of the advantages of CFST, it has been recognized and put into use in engineering. Compared with the hollow sandwich concrete filled steel tube (CFDST), the hollow sandwich concrete filled steel tube not only has its advantages, but also has greater flexural stiffness, less weight and less possibility of structural damage in earthquake. However, the mechanical properties of the components may change after the fire, which may affect the seismic behavior of the components. There have been few reports on this problem at home and abroad, especially after fire, so it is of great significance to explore the hysteretic performance of CFDST components after fire for the future development of composite structures in civil engineering field. The main work of this paper is as follows: (1) the ISO-834 heating curve is used to fire the CFDST components, and then 18 square and circular members are studied by hysteretic experiment. The parameters are hollow ratio, fire time, concrete strength, axial compression ratio and so on. The hysteretic curves, deformation, stiffness and energy dissipation capacity of the components are analyzed. (2) reasonable thermal parameters and ISO-834 heating curves are selected, and the thermal radiation coefficient is determined by comparing with the experimental results. (3) the properties of steel and concrete will change after the fire, and the constitutive structure will also change. The temperature field and mechanical field are fitted together by ABAQUS software, and the calculated curve is compared with the experiment. On the basis of verifying the correctness of the model, the hysteretic curve and deformation of the component are obtained. The stiffness and energy dissipation capacity are analyzed and the interaction between internal and external steel tube and concrete under low cyclic reciprocating load is studied.
【学位授予单位】：沈阳大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU398.9

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