板桁组合结构主桁节点板应力集中系数研究  

Study of Stress Concentration Factor for Main Truss Gusset Plates in Plate-Truss Composite Structure

作　　者：何东升 郑清刚[2] 徐伟[2] HE Dong-sheng;ZHENG Qing-gang;XU Wei(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;China Railway Major Bridge Reconnaissance&Design Institute Co.,Ltd.,Wuhan 430050,China)

机构地区：[1]西南交通大学土木工程学院,四川成都610031 [2]中铁大桥勘测设计院集团有限公司,湖北武汉430050

出　　处：《桥梁建设》2020年第3期46-51,共6页Bridge Construction

基　　金：国家重点研发计划项目(2016YFC0802202)。

摘　　要：为给板桁组合结构节点板的设计提供参考,以沪通长江大桥为背景,针对板桁组合结构的传力特点,采用ANSYS建立节点区域梁段的板壳模型,计算轴力、弯矩单项荷载作用下节点板区域的应力分布特征和应力集中系数。分析弦杆腹板高度、腹杆翼缘宽度、弦杆与腹杆间圆弧半径、腹杆间圆弧半径4个参数对应力集中系数的影响,并拟合出应力集中系数的计算公式。结果表明:单项荷载作用下的应力最大值均出现在所加载的杆件与相邻杆件间的节点板圆弧过渡起始位置;不同杆件在轴力、弯矩作用下的节点板区域应力集中系数不同;下弦杆在轴力、弯矩作用下的节点板区域应力集中系数均较大;下弦杆在轴力作用下的节点板区域应力集中系数与现有公式计算值吻合较好,其他情况下节点板区域的应力集中系数均较现有公式计算值大,需引起重视。To provide reference for the design of gusset plates in the plate-truss composite structure,the Hutong Changjiang River Bridge was taken as the background project.Based on the load transfer characteristics of the plate-truss composite structure,the software ANSYS was used to build the shell element model of the girder sections in the panel point area,to calculate the stress distribution traits in the gusset plate area and stress concentration factors under the actions of pure axial force and bending moment,respectively.The influences of factors on stress concentration,like depth of webs in chords,flange width of web members,radius of the arc between chords and web members,and the radius of the arc between the web members,were analyzed,and the calculation formulas for stress concentration factor were fitted.The results show that the maximum stress appear at the beginning of arc transition of the gusset plates between the members loaded and the adjoining members.Stress concentration factors for different gusset plate areas in different members are different.For the lower chords,the stress concentration factors in the gusset plate areas are all big under the actions of axial force and bending moment.The stress concentration factors of lower chord gained under the axial force agree well with the values calculated by the valid formulas,and the stress concentration factors in other conditions are bigger than the values calculated by the valid formulas,which should be given enough concern.

关 键 词：桥梁工程 板桁组合结构 节点板 应力分布 应力集中系数 参数分析 拟合公式 有限元法 

分 类 号：U443.32[建筑科学—桥梁与隧道工程]