基于断裂力学的钢桥面板纵肋顶板焊缝疲劳效应分析  

Analysis on Fatigue Effect of Rib-to-deck Welded Joints of Steel Bridge Deck Based on Fracture Mechanics

作　　者：王晓 郭亚文 梁爱霞[3] 张莹 张雪松 WANG Xiao;GUO Ya-wen;LIANG Ai-xia;ZHANG Ying;ZHANG Xue-song(Guangxi Communications Design Group Co.,Ltd.,Nanning Guangxi 530029,China;Sichuan Jiaotou Design Consulting Research Institute Co.,Ltd.,Chengdu Sichuan 610041,China;School of Civil Engineering,Southwest Jiaotong University,Chengdu Sichuan 610031,China)

机构地区：[1]广西交通设计集团有限公司,广西南宁530029 [2]四川交投设计咨询研究院有限责任公司,四川成都610041 [3]西南交通大学土木工程学院,四川成都610031

出　　处：《公路交通科技》2023年第3期105-114,共10页Journal of Highway and Transportation Research and Development

基　　金：2021年度广西交通运输行业重点科技项目(202160)。

摘　　要：为了系统研究钢桥面板纵肋顶板焊缝的疲劳效应,基于断裂力学相关理论,依托有限元软件,建立了钢桥面板疲劳裂纹扩展数值模拟方法,并通过实际案例验证了方法的可行性。在此基础上,构建了包含初始裂纹体的钢桥面板RD细节单面焊、RD细节双面焊、RDF细节单面焊和RDF细节双面焊数值有限元分析模型。计算得到了不同细节I型、Ⅱ型和Ⅲ型应力强度因子的纵向历程,获得了等效应力强度因子幅值。经对比分析,确定了钢桥面板纵肋顶板焊缝不利细节,并选取RDF细节双面焊进一步探究了疲劳效应关键影响因素。结果表明:RD细节单面焊、RD细节双面焊、RDF细节单面焊和RDF细节双面焊疲劳裂纹均为I型为主导的Ⅰ-Ⅱ型复合疲劳裂纹;RDF细节单面焊和双面焊等效应力强度因子幅值分别为RD细节的1.5倍和1.2倍;与单面焊相比,RD细节和RDF细节双面焊等效应力强度因子幅值分别降低了12.0%和41.8%,双面焊疲劳性能具有明显优势;就RDF细节双面焊而言,顶板厚度由14 mm增加至18 mm时,疲劳寿命增加915.0万次,初始裂纹深度由0.2 mm增加至1.5 mm时,疲劳寿命降低300.2万次;横隔板厚度、横隔板间距和初始裂纹长度对该细节疲劳寿命影响较小,当裂纹扩展至一定深度后,裂纹形态不再受初始裂纹尺寸的影响,裂纹扁平率将趋于一致。In order to systematically study the fatigue effect of rib-to-deck welded joints of steel bridge deck,based on the relevant theories of fracture mechanics and the finite element software,a numerical simulation method for fatigue crack propagation of steel bridge deck is established,and the feasibility of the method is verified through practical cases.On this basis,the numerical finite element analysis models including RD single-sided welded joints,RD double-sided welded joints,RDF single-sided welded joints and RDF doublesided welded joints of steel bridge deck with the initial crack body are constructed.The longitudinal courses of the stress intensity factors of types I,II and III of different details are got by calculation,and the equivalent stress intensity factor amplitudes are obtained.Through comparative analysis,the unfavorable details of rib-to-deck welded joints of orthotropic steel bridge deck are determined,and RDF double-sided welded joints is selected to further explore the key influencing factors of fatigue effect.The result shows that(1)The fatigue cracks of RD single-sided welded joints,RD double-sided welded joints,RDF single-sided welded joints and RDF double-sided welded joints are all type I-II composite fatigue cracks dominated by type I.(2)The amplitudes of equivalent stress intensity factors of RDF single-sided and double-sided welded joints are 1.5 times and 1.2 times of those of RD welded joints respectively.(3)Compared with single-sided welded joints,the amplitudes of equivalent stress intensity factors of RD and RDF double-sided welded joints are reduced by 12.0%and 41.8%respectively,and the fatigue performance of double-sided welded joints has obvious advantages.(4)As for RDF double-sided welded joints,the fatigue life is increased by 9.15 million times when the deck thickness is increased from 14 mm to 18 mm,and the fatigue life is reduced by 3.002 million times when the initial crack depth is increased from 0.2 mm to 1.5 mm.(5)The thickness,spacing and initial crack length of the dia

关 键 词：桥梁工程 钢桥面板 纵肋顶板焊缝 断裂力学 疲劳效应 影响因素 

分 类 号：U441.4[建筑科学—桥梁与隧道工程]