钢桥面板顶板与U肋焊缝裂纹类型及扩展特征  

Crack types and propagation characteristics of the U rib-to-deck joint weld of orthotropic steel bridge decks

作　　者：傅慧 吉伯海[1] 徐捷[1] 袁周致远 FU Hui;JI Bohai;XU Jie;YUAN Zhouzhiyuan(School 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,南京210098

出　　处：《扬州大学学报（自然科学版）》2021年第2期66-72,共7页Journal of Yangzhou University：Natural Science Edition

基　　金：中国科学技术交流中心国家重点研发计划专项资助项目(2017YFE0128700);江苏苏通大桥有限责任公司科技资助项目(2019)。

摘　　要：为研究顶板与U肋焊缝各类型疲劳裂纹萌生及扩展特征,利用ABAQUS有限元软件建立钢桥面板节段模型,根据最大主应力及其方向分布,分析了不同轮载下的裂纹萌生位置和开裂趋势.结合顶板、U肋的受力与变形特征,利用FRANC2D二维断裂分析软件建立该疲劳细节开裂模型,通过分析扩展路径和应力强度因子,明确顶板与U肋各类型裂纹的受力成因与扩展特征.研究结果表明:当轮载横向位置偏离U肋正上方时,裂纹易萌生于焊根处;而轮载作用于U肋正上方时,裂纹易萌生于焊趾处;水平裂纹易在焊根处萌生并沿焊喉方向扩展,且焊根裂纹扩展的可能性和速率远大于焊趾处,尤其当U肋变形较大时.顶板、U肋面外变形分别易导致张开型的竖向和水平向扩展裂纹.In order to study the initiation and propagation characteristics of various types of fatigue cracks of the rib-to-deck joint weld,a segment model of steel bridge deck was established by ABAQUS finite element software.According to the distribution of the maximum principal stress and its direction,the crack initiation position and trend under different wheel loads are analyzed.Combined with the stress and deformation characteristics of the deck and U-rib,the fatigue detail cracking model is established by FRANC2 D.The stress causes and propagation characteristics of various types of cracks of the rib-to-deck joint weld are determined by analyzing the propagation path and stress intensity factor.The results show that when the lateral position of wheel load deviates from the top of U-rib,cracks are more inclined to initiate at the weld root than at the weld toe.Whlie the wheel load acts on the upper part of the U-rib it is easy to initiate at the welding toe.Horizontal cracks are more likely to initiate at the weld root and propagate along the weld throat,and the probability and rate of crack propagation at the weld root are much greater than those at the weld toe,especially when the U-rib deformes greatly.The out-of-plane deformation of the deck and the U-rib are easy to cause vertical and horizontal expansion cracks respectively.

关 键 词：钢桥面板 顶板-U肋焊缝 裂纹类型 面外变形 裂纹萌生 扩展特征 

分 类 号：U448.36[建筑科学—桥梁与隧道工程]