椭圆钢管混凝土受扭、受剪和局压性能与设计方法研究

发布时间：2018-06-27 11:39

本文选题：椭圆钢管混凝土 + 数值分析　；参考：《合肥工业大学》2017年硕士论文

【摘要】：椭圆钢管混凝土是由椭圆钢管和核心混凝土组成的新型钢管混凝土构件,具有承载力高、塑性性能好和施工快捷等优点。此外,椭圆钢管混凝土沿长轴方向可以减小流体阻力,通过调节长短轴比可适应不同的受力情况,应用在建筑中还具备独特的美学效果,备受研究学者和建筑设计人员的青睐,现已逐步应用于机场航站楼、火车站和桥墩等工程实例中。然而,目前对于椭圆钢管混凝土的研究仅限于轴压、压弯和受弯性能上,对受扭、受剪和局压性能的研究寥寥无几。因此,为系统研究椭圆钢管混凝土的各项力学性能,有必要对椭圆钢管混凝土在受扭、受剪和局压状态下的力学性能和设计方法进行研究。本文通过数值分析方法研究了两种椭圆形截面的钢管混凝土:尖椭圆钢管混凝土和平椭圆钢管混凝土。本文研究的具体工作如下:(1)通过ABAQUS分别对两种椭圆形截面的钢管混凝土构件建立了在纯扭作用下的数值分析模型。考虑了几何特征、材料非线性和钢管-混凝土接触关系,对构件的受扭性能开展了诸多参数分析,研究参数包括钢材强度、混凝土强度、截面含钢率、截面面积和长短轴比,揭示了构件在纯扭状态下的破坏模态和受力机理。(2)利用ABAQUS分别沿长轴和短轴方向建立了两种椭圆形截面的钢管混凝土受剪构件有限元分析模型。分析了构件在受剪状态下的破坏模式和受力机理。系统地开展了构件受剪性能的参数分析,分别在长轴和短轴方向上研究了剪跨比、钢材强度、混凝土强度、截面含钢率、长短轴比和截面面积等参数对椭圆钢管混凝土构件抗剪承载力的影响规律。(3)通过ABAQUS分别对两种椭圆形截面的钢管混凝土短柱建立了在局压作用下的数值分析模型。对短柱的局压性能进行了系统的参数分析,研究了局压面积比、钢材和混凝土强度、含钢率、长短轴比和截面面积等对局压短柱荷载(N)-变形(Δ)曲线和局压承载力的影响,揭示了在局压作用下椭圆钢管混凝土短柱的破坏模式和受力机理。(4)基于统一理论与叠加原理,结合本文所做的参数分析和受力机理研究,对椭圆钢混凝土的设计方法做出了深入探讨。针对椭圆钢管混凝土在受扭、受剪以及局压作用,提出了尖椭圆钢管混凝土和平椭圆钢管混凝土的简化计算公式,为建立椭圆钢管混凝土构件设计方法提供了参考依据。
[Abstract]:Concrete filled elliptical steel tube (CFST) is a new type of concrete filled steel tube (CFST) composed of elliptical steel tube and core concrete, which has the advantages of high bearing capacity, good plasticity and quick construction. In addition, the elliptical concrete-filled steel tube (CFST) along the long axis can reduce the fluid resistance. By adjusting the ratio of the long axis to the long axis, it can adapt to different stress conditions, and it also has a unique aesthetic effect in the architecture, so it is favored by researchers and architectural designers. Has been gradually used in airport terminals, railway stations and piers and other engineering examples. However, at present, the research on concrete filled elliptical steel tubes is limited to axial compression, compression and bending performance, but the research on torsional, shear and local compression performance is rare. Therefore, in order to systematically study the mechanical properties of concrete filled elliptical steel tubes, it is necessary to study the mechanical properties and design methods of concrete filled elliptical steel tubes under torsion, shear and local pressure. In this paper, two kinds of elliptical section concrete filled steel tubular concrete: tip elliptical steel tube concrete and elliptical concrete filled steel tube are studied by numerical analysis method. The main work of this paper is as follows: (1) the numerical analysis models of two kinds of concrete filled steel tube members with elliptical section are established by Abaqus under pure torsion. Taking into account the geometric characteristics, material nonlinearity and the contact relationship between steel tube and concrete, the torsional properties of the members are analyzed. The parameters include steel strength, concrete strength, steel content ratio of section, cross-section area and long-axis ratio. The failure mode and stress mechanism of members under pure torsion are revealed. (2) two finite element analysis models of concrete-filled steel tubular members with elliptical section are established by Abaqus along the long axis and short axis respectively. The failure mode and stress mechanism of the member under shear condition are analyzed. The parameter analysis of the shear behavior of the member is carried out systematically. The shear span ratio, steel strength, concrete strength and steel content of the section are studied in the long axis and the short axis direction, respectively. The influence of axial ratio and cross-section area on the shear capacity of concrete filled elliptical steel tube members is studied. (3) the numerical analysis models of two kinds of elliptical concrete filled steel tubular short columns under local pressure are established by Abaqus. The local compression properties of short columns are systematically analyzed, and the effects of local pressure area ratio, strength of steel and concrete, steel content ratio, long axis ratio and section area on load (N) -deformation (螖) curve and local compression bearing capacity of local compression short columns are studied. The failure mode and stress mechanism of elliptical concrete-filled steel tubular short columns under partial compression are revealed. (4) based on the unified theory and the superposition principle, the parameter analysis and stress mechanism are studied in this paper. The design method of elliptical steel concrete is discussed. In view of the torsion, shear and local compression of concrete filled elliptical steel tubes, a simplified calculation formula of concrete filled elliptical steel tubes with pointed elliptical steel tubes and concrete filled elliptical steel tubes is put forward, which provides a reference for the design method of concrete filled elliptical steel tube members.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU398.9

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