钢桁梁桥横梁与弦杆节点切削的疲劳性能提升方法  

Fatigue performance improvement method for crossbeam and chord joints by cutting operation in steel truss bridge

作　　者：李传喜 吉伯海[1] 傅中秋[1] 姚悦[1] Li Chuanxi;Ji Bohai;Fu Zhongqiu;Yao Yue(College of Civil and Transportation Engineering,Hohai University,Nanjing 210098,China)

机构地区：[1]河海大学土木与交通学院,江苏南京210098

出　　处：《南京理工大学学报》2023年第1期133-140,共8页Journal of Nanjing University of Science and Technology

基　　金：国家重点研发计划(2017YFE0128700);江苏省交通运输科技与成果转化项目(2019Y69)。

摘　　要：为了降低横梁与弦杆节点开裂风险,提出了一种节点切削的疲劳性能提升方法。通过建立钢桁梁桥有限元模型,明确了横梁腹板间隙疲劳开裂的根本成因。基于开裂成因,对横梁端部上翼缘进行切削,通过对比不同切削参数对局部细节受力特征的影响,得到了合理的切削参数范围。结果表明,桥面混凝土板与纵梁对横梁约束是腹板间隙开裂的根本成因;上翼缘切削有效地改善了腹板间隙受力状态,降低了开裂风险;建议切削点至焊缝的距离取30~70 mm,切削半径取75~150 mm。In order to reduce the risk of cracking at joints between crossbeam and chord,an improving method for fatigue performance based on joint cutting is proposed.Based on the finite element model of steel truss bridge,the basic reason for fatigue crack in the web gap of crossbeam is clarified.Based on the cause of cracking,the upper flange of crossbeam end is cut.By comparing the effects of different cutting parameters on mechanical characteristics of local details,reasonable range of cutting parameters is obtained.The results show that the restraint of concrete deck slab and longitudinal beam to the crossbeam is the fundamental cause of web gap cracking.Cutting the upper flange can effectively improve the stress state of web gap and reduce the risk of cracking.The recommended distance between the cutting point and weld is 30 mm to 70 mm with the cutting radius of 75 mm to 150 mm.

关 键 词：钢桁梁桥 腹板间隙 面外变形 节点切削 疲劳性能提升 

分 类 号：U448.36[建筑科学—桥梁与隧道工程]