钢结构桥梁具有轻质高强、跨越能力大、易工厂化制造和便于装配化施工等突出优点，是我国桥梁工程的重要发展方向。但工程实践表明，疲劳与断裂是导致结构服役性能降低甚至引发灾难性事故，仍是制约钢结构桥梁发展应用的关键因素。国内外学者从不同的角度对于钢结构桥梁疲劳问题进行了深入系统的研究，现聚焦疲劳失效机理与抗力评估方法、抗疲劳设计与建造技术、环境因素及其疲劳抗力效应机制、疲劳裂纹识别与监测检测、疲劳开裂处置与性能强化等主要方面，对2020年度国内外学者在相关领域所取得的最新研究进展进行总结，梳理亟待解决的关键问题以及下阶段的研究重点。结果表明：钢结构桥梁疲劳问题是学术界和工程界的研究热点，在对疲劳性能分析评估理论方法、抗疲劳设计和长寿命结构、抗疲劳建造技术、疲劳损伤监测与疲劳微裂纹检测识别、剩余疲劳寿命预测与疲劳性能强化进行研究的基础上，构建钢结构桥梁全寿命周期抗疲劳技术，是本领域的研究重点和重要发展方向。

Steel bridge has outstanding advantages, such as high ratio of strength to weight, large span capacity, easy to factory manufacturing and assembly construction, where bridge engineering is going in the further. However, the engineering practice shows that fatigue and fracture are the decisive factors to reduce the service performance of steel structure and cause catastrophic accidents, which seriously restrict the development and application of steel bridges. The in-depth and systematic researches on this practical engineering problem from different perspectives have been have conducted at home and abroad. To clarify the urgent problems and determine the research focuses and development directions in the next stage, the latest research progress in fatigue of steel bridge are summarized, including fatigue failure mechanism and fatigue resistance assessment method, anti-fatigue design and construction technology, environmental factors and their effect mechanism to fatigue resistance, fatigue crack identification, monitoring and detection, fatigue crack treatments and fatigue performance enhancement. The results demonstrate that the fatigue issue is a hot topic to researchers and engineers. the researches on fatigue critical problems in steel bridge has made adequate progress. Based on the studies including anti-fatigue design method, structures with high fatigue resistance, fatigue resistance assessment method, construction technology, fatigue damage monitoring and fatigue micro-crack identification, remaining fatigue life prediction and fatigue performance enhancement, it is the research emphasis and future directions to establish the fatigue resistance technology of steel bridges in life cycle.

国家自然科学基金（51878561、51978579、51758533、51578455）；广东省重点领域研发计划项目（2019B111106002）桥梁结构健康与安全国家重点实验室开放课题重点项目（BHSKL18-01-KF）；四川省科技计划项目（2021YJ0037）