新型方钢管混凝土柱—外包U形钢混凝土梁节点抗剪性能研究

发布时间：2018-07-05 07:12

本文选题：方钢管混凝土柱 + 外包U形钢混凝土组合梁　；参考：《山东建筑大学》2017年硕士论文

【摘要】：方钢管混凝土柱-外包U形钢混凝土组合梁构成的结构体系是近些年新兴的一种钢-混凝土组合结构形式,具有承载力高、刚度大、稳定性好、施工便捷、综合效益高等优点,已越来越受到工程界和学术界的普遍关注。本文基于本课题组提出的方钢管混凝土柱-外包U形钢混凝土组合梁隔板贯通钢筋截断式节点,提出了改善负弯矩钢筋与钢管柱连接处受力性能的一种新型节点形式-隔板贯通钢筋套筒式节点,并利用ABAQUS有限元分析软件对新型节点进行了抗剪性能的研究,主要有如下工作和成果:(1)利用ABAQUS软件对本课题组完成的方钢管混凝土柱-外包U形钢混凝土组合梁隔板贯通钢筋截断式节点试验进行了低周往复荷载作用下的有限元模拟,有限元分析结果与试验结果在节点变形、应力分布、破坏形态、滞回曲线以及骨架曲线等方面均吻合较好。(2)基于验证的有限元模型,针对新型节点试件,设计了发生节点域剪切破坏的有限元试件,对其进行三维非线性有限元分析,探讨了节点的破坏形态和节点变形,较为精确地分析了节点的应力分布规律、传力机制以及抗剪承载力。研究结果表明:节点核心区由原来的矩形变成了平行四边形,节点发生了明显的剪切变形;节点核心区的抗剪承载力主要由核心区方钢管柱腹板和混凝土共同承担,核心区混凝土主要在沿对角线方向形成“斜压杆”来抵抗梁端翼缘的压力;而核心区钢管柱腹板则主要通过在对角线形成“斜拉杆”来抵抗节点的外力。(3)对新型节点进行抗剪承载力参数化分析,研究影响节点抗剪承载力的主要因素和影响规律。研究结果表明:混凝土翼板的厚度、柱截面含钢率、钢管柱钢材强度对节点域极限抗剪承载力的影响较大;钢管柱混凝土强度以及贯通隔板的厚度对节点极限抗剪承载力的影响有限;当轴压比为0-0.3时,适当增大方钢管混凝土柱的轴压比可在一定程度上提高节点的极限抗剪承载力,当轴压比为0.3-0.6时,轴压比对节点极限抗剪承载力的影响不大;混凝土翼板的宽度对节点极限抗剪承载力几乎没有影响。(4)提出新型节点的极限抗剪承载力简化公式,并将简化公式的计算结果与有限元计算结果进行比较,两者吻合较好,具有一定的适用性。
[Abstract]:The structural system composed of concrete-filled square steel tube column and U-shaped steel reinforced concrete composite beam is a new type of steel-concrete composite structure in recent years. It has the advantages of high bearing capacity, high stiffness, good stability, convenient construction, high comprehensive benefit and so on. It has been paid more and more attention by the engineering and academic circles. Based on the concrete filled square steel tube column and U-shaped steel concrete composite beam partition plate proposed by our group, the steel bar truncated joint is used in this paper. In this paper, a new type of joint form, that is, the diaphragm through steel bar sleeve joint, is proposed to improve the behavior of negative moment steel bar and steel pipe column. The shear behavior of the new joint is studied by using Abaqus finite element analysis software. The main works and achievements are as follows: (1) finite element simulation is carried out under low-cycle reciprocating load to test the truncated joint of concrete-filled square steel tubular column and U-shaped steel concrete composite beam, which is completed by our research group with Abaqus software. The results of finite element analysis agree well with the experimental results in the aspects of joint deformation, stress distribution, failure morphology, hysteretic curve and skeleton curve. (2) based on the validated finite element model, a new type of joint specimen is proposed. The finite element specimens with shear failure in the joint domain are designed and analyzed by three dimensional nonlinear finite element method. The failure patterns and joint deformation of the joints are discussed, and the stress distribution law of the joints is analyzed more accurately. Force transfer mechanism and shear capacity. The results show that the core region of the joint is changed from rectangle to parallelogram, and the shear capacity of the joint is mainly borne by the web plate and concrete of square steel pipe column in the core area. The concrete in the core area mainly forms "oblique compression bar" along diagonal direction to resist the pressure of the flange at the end of the beam. On the other hand, the web plate of steel tube column in the core area is mainly used to resist the external force of the joint by forming diagonal "diagonal bar". (3) the parametric analysis of the shear bearing capacity of the new joint is carried out, and the main factors affecting the shear bearing capacity of the joint and the influencing law are studied. The results show that the thickness of concrete flange, the steel content of column section and the steel strength of steel pipe column have great influence on the ultimate shear bearing capacity in the joint region. When the axial compression ratio is 0-0.3, the ultimate shear capacity of joints can be improved by increasing the axial compression ratio of concrete-filled steel tubular columns. When the axial compression ratio is 0.3-0.6, the axial compression ratio has little effect on the ultimate shear bearing capacity of the joints, and the width of the concrete flange has little effect on the ultimate shear bearing capacity of the joints. (4) A simplified formula for the ultimate shear bearing capacity of the new joints is proposed. The calculated results of the simplified formula are compared with those of the finite element method, which are in good agreement with each other and have certain applicability.
【学位授予单位】：山东建筑大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU398.9

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