轴力作用下焊接方管Π型节点的极限承载力分析  

Analysis of the Ultimate Bearing Capacity of the Π-Joint of Welded Square Tube Under Axial Load

作　　者：刘岩[1] 陈奕贤 王鑫 樊晨阳 武艳如[1] LIU Yan;CHEN Yixian;WANG Xin;FAN Chenyang;WU Yanru(School of Civil Engineering,Chang’an University,Xi’an 710061,Shaanxi,China)

机构地区：[1]长安大学建筑工程学院,西安710061

出　　处：《华南理工大学学报（自然科学版）》2024年第11期32-42,共11页Journal of South China University of Technology(Natural Science Edition)

基　　金：陕西省博士后基金资助项目(2023BSHTBZZ35)。

摘　　要：目前规范中还未规定Π型构造形式的方管节点承载力计算公式。该文在经过试验验证有限元分析准确性的基础上,基于两种方管不同区域的材料本构关系模型,利用Abaqus软件对85组在轴力作用下的节点进行了数值模拟,得到了方管Π型节点在轴力作用下的极限承载力。随后,通过参数化分析和多元回归,得出影响Π型节点极限承载力的因素以及修正的承载力计算公式。结果表明,支管-主管宽度比β对节点极限承载力和初始刚度影响较大,增大支管宽度,能够显著提高节点的极限承载力,支管上施加的荷载由主管上表面的抗弯、抗剪作用和主管侧壁共同承担,节点的破坏模式也取决于β;主管宽厚比2γ越大,意味着主管上翼缘和支管连接区域变得更加细长,降低了主管上翼缘的抗弯刚度,节点承载力和初始刚度因此降低;支管-主管高宽比η和支管间距g对节点极限承载力有一定影响,增大支管截面的高度和支管间隙,即增大了沿主管纵向方向的支管、主管相交区域,使得支管在主管翼缘更宽的区域传递荷载,节点的塑性区域更大,材料利用更充分,因此提高了节点的承载能力;支管-主管厚度比τ对节点极限承载力和初始刚度影响不大,支管的壁厚增加,提高了支管的承载力,但节点最终破坏是主管上翼缘达到屈服破坏而并非支管破坏,因此支管厚度的变化对节点承载能力影响不明显。根据有限元模型的分析结果,通过曲线拟合提出了计算方管Π型节点极限承载力的参数方程,并对该方程的准确性进行了评价,为这类节点的进一步研究和工程应用提供了参考。The current standards have not yet specified the formula for calculating the bearing capacity of Π-shaped welded square tube joints.Based on experimental validation of finite element analysis accuracy,this paper utilizes Abaqus software to numerically simulate 85 sets of joints under axial load,obtaining the ultimate bearing capacity ofΠ-shaped joints.Subsequently,parameter analysis and regression analysis were conducted to identify factors influencing the ultimate bearing capacity ofΠ-shaped joints and the modified calculation formula.The results show that the width ratio of branch pipe to main pipeβhas a great influence on the ultimate bearing capacity and initial stiffness of the joint.Increasing the width of branch pipe can significantly improve the ultimate bearing capacity of the joint.The load imposed on the branch pipe is jointly borne by the bending and shear effects on the upper surface of the main pipe and the side wall of the main pipe.The failure mode of the joint also depends onβ.The larger the width thickness ratio of the main pipe 2γ,it means that the connection area between the upper flange of the main pipe and the branch pipe becomes more slender,which reduces the bending stiffness of the upper flange of the main pipe,and therefore reduces the bearing capacity and initial stiffness of the joint.The branch pipe to main pipe height width ratioηand the branch pipe spacing have a certain impact on the ultimate bearing capacity of the joint.Increasing the height of the branch pipe section and the branch pipe clearance,that is,increasing the intersection area of the branch pipe and the main pipe along the longitudinal direction of the main pipe,makes the branch pipe transfer load in the wider area of the main pipe flange.The plastic area of the node is larger and the material is more fully utilized,thus improving the carrying capacity of the node.The thickness ratio of branch pipe to main pipeτhas little effect on the ultimate bearing capacity and initial stiffness of the joint.The increase of

关 键 词：焊接方管节点 轴力作用 方管材料特性 极限承载力 有限元分析 

分 类 号：TU391[建筑科学—结构工程]