多因素耦合作用下高强钢焊缝连接疲劳性能研究进展  

Research Progress on Fatigue Performance of Welded Joints of High-Strength Steel Under Multi-factor Coupling Effect

作　　者：郭宏超[1] 关晓迪 王铳 赵越 GUO Hongchao;GUAN Xiaodi;WANG Chong;ZHAO Yue(School of Civil Engineering and Architecture,Xi'an University of Technology,Xi'an 710048,China)

机构地区：[1]西安理工大学土木建筑工程学院,西安710048

出　　处：《建筑钢结构进展》2024年第11期1-14,共14页Progress in Steel Building Structures

基　　金：国家自然科学基金(51978571);陕西省杰出青年基金(2021JC-41);陕西省重点研发计划(2022SF-199)。

摘　　要：焊接是钢结构广泛采用的连接形式。在提高钢材强度等级后,焊接接头在服役过程中对蚀坑、裂纹等缺陷的敏感度增强,且焊接会劣化钢材成分、组织性能进而导致焊接接头产生初始缺陷。因此,在环境腐蚀、应力集中、超载等因素作用下,钢结构焊缝连接未达到设计服役年限就发生疲劳断裂,造成严重的资源浪费。基于对多因素耦合下高强钢焊缝连接疲劳性能研究现状的总结,介绍了腐蚀疲劳机理及腐蚀预测模型,分析了疲劳设计方法及疲劳寿命评估理论,归纳了焊接残余应力、点蚀坑以及初始裂纹对焊缝连接疲劳性能的影响。结果表明:焊接工艺、焊接参数以及焊接几何尺寸等对焊接接头的力学性能影响显著,焊接残余应力会削弱高强钢焊接接头的疲劳强度,焊接缺陷会引起应力集中现象,加快裂纹萌生速度;高强钢在腐蚀初期形成点蚀坑并逐渐发展成裂纹,进而导致焊缝连接的腐蚀疲劳性能降低。随着高强钢焊缝连接在工程中的应用增多,建议开展不同强度等级及焊接形式的焊缝连接疲劳试验,并将理论成果和经验方法在实际工程中推广应用。Welding is the most widely used connection form for steel structures.After the steel strength grade is increased,the sensitivity of welded joints to defects such as corrosion pit and crack increases during service.And due to the deterioration of steel composition and structural properties caused by welding,initial defects are produced in the welded joint.Furthermore,under the influence of environmental corrosion,stress concentration,overload and other factors,fatigue fracture occurs in the welded joints of steel structures before reaching the designed service life,resulting in serious resource waste.This paper summarizes the research status of fatigue performance of welded joints of high-strength steel under multi-factor coupling effect,introduces the mechanism of corrosion fatigue and corrosion prediction model,analyzes the fatigue design method and fatigue life assessment theory,and summarizes the influence of welding residual stress,corrosion pit and initial crack on the fatigue performance of welded joints.The results show that the selection of welding process,welding parameters and welding geometric dimensions has a significant impact on the mechanical properties of welded joints.The presence of welding residual stress can weaken the fatigue strength of welded joints of high-strength steel,and welding defects can cause stress concentration and accelerate crack initiation.In the early stage of corrosion,corrosion pits are formed on the surface of high-strength steel,which gradually develop into cracks,leading to a decrease in the corrosion fatigue performance of welded joints.With the increasing application of high-strength welded joints in engineering,it is necessary to conduct fatigue tests on welded joints of different strength grades and welding forms,in order to promote the application of theoretical achievements and empirical methods in engineering practice.

关 键 词：多因素耦合作用 高强钢 焊缝连接 疲劳性能 焊接残余应力 点蚀坑 初始裂纹 

分 类 号：TU311.3[建筑科学—结构工程]