【作者】 张鹏；

【导师】 张素梅；

【作者基本信息】 哈尔滨工业大学 ， 土木水利（专业学位）， 2023， 硕士

【摘要】 钢管混凝土柱具有强度高、抗震性能好、施工速度快和抗火性能好等优点,在实际工程中得到广泛应用。传统的方形、矩形和圆形的钢管混凝土柱在住宅建筑中应用时常常在室内墙角处凸出,影响房间的正常使用和家具摆放。采用与建筑墙体等厚的钢管混凝土异形柱能够避免结构柱占用室内空间,保证了室内空间的方正性和布置的灵活性,有着更广阔的发展前景。本论文主要针对十字形钢管混凝土异形柱与钢梁的节点开展研究,在节点处钢梁上下翼缘通过偏置的竖向肋板连接,同时在柱壁内部焊接钢筋保证节点弯矩和剪力的有效传递;采用试验和有限元模拟相结合的方法分析了所提出节点的滞回性能,主要工作及取得的成果如下:设计并制作了2个缩尺比为1:2的十字形钢管混凝土柱-钢梁节点试件,竖向肋板向上偏置减小连接件凸出,保证室内使用高度;在钢管柱内壁节点域高度范围内焊接钢筋,保证节点剪力传递,避免钢管壁发生剪切破坏。进行了十字形钢管混凝土柱-钢梁节点试件在柱端往复荷载作用下的拟静力试验及相关材性试验,在钢管混凝土柱内节点域高度分别采用加密的钢筋桁架或多腔钢板两种加劲方法。测量获得钢管柱水平位移、梁端竖向位移、节点域转角及部分区域材料应变等数据,观测了节点破坏过程和破坏模式,分析得到试件的滞回曲线、延性和变形能力、耗能能力、强度退化规律、刚度退化规律等抗震性能指标。试验结果表明,偏置竖向肋板具有足够的传递节点弯矩的能力,柱壁内部节点域高度焊接钢筋可以有效传递节点剪力;节点区采用两种加劲方式的钢管混凝土异形柱-钢梁节点的破坏模式均为梁端破坏,塑性铰出现在钢梁翼缘与竖向肋板相交处;柱端水平荷载-层间相对位移关系曲线饱满,抗震性能良好,其中加劲形式为加密钢筋桁架的节点有更好的延性表现。利用ABAQUS有限元软件建立了十字形钢管混凝土异形柱-钢梁节点的精细化模型,混凝土应力-应变关系选用塑性损伤模型,钢材应力-应变关系选用线性随动强化模型。对有限元模拟结果进行分析,得到节点柱端水平荷载-层间相对位移滞回曲线、骨架曲线、关键部位破坏形态和节点塑性铰发展规律。进行了节点域受力机理分析,得到节点核心区钢管、混凝土、钢梁的应力分布规律,进一步明晰了节点传力模式。采用精细的有限元分析模型对节点进行了参数分析,研究了钢管混凝土柱轴压比、材料强度、竖向肋板厚度、节点域柱内加劲形式等参数对十字形钢管混凝土异形柱-钢梁节点滞回性能的影响。有限元结果表明,节点设计传力明确,受力性能良好;竖向肋板增强了梁端部承载力,使梁端塑性铰外移,实现强柱弱梁、节点更强。提出了十字形钢管混凝土异形柱-钢梁节点的构造措施和设计建议。更多还原

【Abstract】 Concrete-filled steel tube columns have the advantages of high strength,good seismic performance,fast construction speed and good fire resistance,and are widely used in practical engineering.When traditional square,rectangular and circular steel pipe concrete columns are used in residential buildings,they often protrude at the corners of the interior walls,which affects the normal use of the room and the placement of furniture.The use of special-shaped steel pipe concrete columns with the same thickness as the building wall can avoid the structural columns from occupying the indoor space,ensure the squareness of the indoor space and the flexibility of layout,and have a broader development prospect.This paper mainly studies the joints between cross-shaped concrete-filled steel tube special-shaped columns and steel beams.At the joints,the upper and lower flanges of steel beams are connected by offset vertical ribs.At the same time,steel bars are welded inside the column walls to ensure joint bending moments and shear forces.The effective transmission of the node;the hysteretic performance of the proposed node was analyzed by combining the test and the finite element simulation method.The main work and achievements are as follows:Two cross-shaped concrete-filled steel tube column-steel beam joint specimens with a scale ratio of 1:2 were designed and produced,and the vertical ribs were offset upwards to reduce the protrusion of the connecting parts to ensure the indoor use height;The steel bars are welded within the height range of the domain to ensure the transmission of shear force at the joints and avoid shear failure of the steel pipe wall.The quasi-static test and related material property tests of the cross-shaped concretefilled steel tube column-steel beam joint specimens under the reciprocating load at the column end were carried out.A strengthening method.The horizontal displacement of the steel pipe column,the vertical displacement of the beam end,the rotation angle of the joint domain and the material strain in some areas were obtained by measurement,the failure process and failure mode of the joint were observed,and the hysteretic curve,ductility and deformation capacity,and energy dissipation capacity of the specimen were analyzed,strength degradation law,stiffness degradation law and other seismic performance indicators.Th e test results show that the offset vertical ribs have sufficient ability to transmit the joint bending moment,and the welded steel bars at the height of the internal joint area of the column wall can effectively transmit the joint shear force;The failure mode of the joints is beam end failure,and the plastic hinge appears at the intersection of the steel beam flange and the vertical rib;the relationship curve between the horizontal load at the column end and the relative displacement between stories is full,and the seismic performance is good,and the stiffening form is the joint of the dense steel truss Have better ductility performance.The refined model of the cross-shaped CFST special-shaped column-steel beam joint is established by using ABAQUS finite element software.The stress-strain relationship of concrete adopts the plastic damage model,and the stress-strain relationship of steel adopts the linear kinematic strengthening model.By analyzing the finite element simulation results,the hysteretic curve,skeleton curve,failure form of key parts and the development law of the joint plastic hinge are obtained.The force mechanism of the node domain was analyzed,and the stress distribution law of the steel pipe,concrete,and steel beam in the core area of the node was obtained,and the force transmission mode of the node was further clarified.The detailed finite element analysis model is used to analyze the parameters of the joints,and the parameters such as the axial compression ratio of the CFST column,the material strength,the thickness of the vertical rib,and the stiffening form in the column in the node domain are studied.The impact of node hysteresis performance.The finite element results show that the force transmission of the joint design is clear,and the mechanical performance is good;the vertical ribs enhance the bearing capacity of the beam end,and the plastic hinge at the beam end moves outward,realizing strong columns and weak beams,and stronger joints.Structural measures and design suggestions for cross-shaped CFST special-shaped column-steel beam joints are proposed.更多还原