顶板-纵肋焊接细节残余应力的松弛效应  

Relaxation effect of welding residual stress in deck-to-rib joints

作　　者：钟雯 丁幼亮[1] 宋永生[2] 曹宝雅 耿方方[3] ZHONG Wen;DING You-liang;SONG Yong-sheng;CAO Bao-ya;GENG Fang-fang(Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education,Southeast University,Nanjing 210096,China;College of Architecture Engineering,Jinling Institute of Technology,Nanjing 211196,China;College of Architecture Engineering,Nanjing Institute of Technology,Nanjing 211167,China)

机构地区：[1]东南大学混凝土及预应力混凝土结构教育部重点实验室,江苏南京210096 [2]金陵科技学院建筑工程学院,江苏南京211196 [3]南京工程学院建筑工程学院,江苏南京211167

出　　处：《浙江大学学报（工学版）》2020年第1期83-90,共8页Journal of Zhejiang University：Engineering Science

基　　金：国家自然科学基金资助项目（51978154,51608258）;江苏省杰出青年基金资助项目（BK20190013）;东南大学优秀博士学位论文培育基金资助项目（YBJJ1819)

摘　　要：为了准确把握钢桥面顶板-纵肋焊缝位置的真实拉、压状态和应力比对正交异性钢桥面板(OSD)疲劳寿命的影响,通过建立焊接残余应力与车载应力的耦合应力分析模型,构建焊接残余应力和车辆荷载耦合作用下的应力比、等效应力幅等疲劳参数计算方法,形成了焊接残余应力与车载应力的耦合应力精细化计算方法.以江阴长江大桥为例,应用该方法,开展车辆荷载和残余应力场对疲劳损伤的定量分析.案例分析表明,焊缝位置残余拉应力在叠加了以拉应力为主的循环车载应力后,纵、横向应力松弛大小均超过车载应力峰值,出现明显的应力松弛现象,而叠加以压应力为主的循环车载应力后,应力松弛效应不明显;与仅考虑车载应力作用下的焊缝位置应力状态相比,考虑焊接残余应力和车载应力耦合作用之后,压应力循环工况焊缝位置疲劳应力状态发生了本质变化,即由不需要进行疲劳验算的压应力状态变为拉应力状态;拉应力循环工况的疲劳状态虽未改变,但该状态下焊缝位置的疲劳寿命由无限变为有限.A coupled stress analysis model that considers the welding residual stress and vehicle stress was established in order to accurately analyze the influence of the actual tension and compression state and stress ratio at the deck-to-rib welding seam position on the fatigue life of an orthotropic steel deck(OSD).The calculation of the fatigue parameters,including the stress ratio and equivalent stress amplitude,enables the development of a refined calculation method for the coupling stress between the welding residual stress and vehicle stress.A qualitative analysis of the fatigue life under the vehicle load and residual stress field was conducted using the proposed method by taking the Jiangyin Yangtze River Bridge as an example.A case analysis show that when the residual tensile stress in the welding seam position is superimposed on the mainly tensile cyclic vehicle load stress,the longitudinal and transverse stress relaxation exceeds the peak vehicle load stress and significant stress relaxation occurred.When the residual tensile stress in the welding seam position is superimposed on the mainly compressive cyclic vehicle load stress,the relaxations of both the longitudinal and transverse stresses are not obvious.Compared with the stress state of the welding point under the action of only the vehicle stress,when the coupling effect of the welding residual stress and vehicle stress is considered,the fatigue stress state of the welding point has undergone an essential change under cyclic compressive stress,that is,the compressive stress state that does not require a fatigue check is changed to the tensile stress state.Although the fatigue state of the tensile stress cycle condition has not changed,the fatigue life of the welding point changes from infinite to finite under the tensile condition.

关 键 词：正交异性钢桥面板(OSD) 应力松弛效应 顶板-纵肋细节 焊接残余应力 耦合应力 

分 类 号：TU318[建筑科学—结构工程]