多 因 素 耦 合 作 用 下 高 强 钢 焊 缝 连 接 疲 劳 性 能 研 究 进 展

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.