钢桥疲劳裂纹扩展行为研究及可靠度更新分析  

Study of fatigue crack growth behavior and reliability update analysis of steel bridges

作　　者：苏三庆[1] 李俊廷 王威[1] 刘馨为 左付亮 邓瑞泽 Su Sanqing;Li Junting;Wang Wei;Liu Xinwei;Zuo Fuliang;Deng Ruize(Xi'an University of Architecture and Technology,Xi'an 710055,China)

机构地区：[1]西安建筑科技大学,陕西西安710055

出　　处：《土木工程学报》2024年第7期1-9,70,共10页China Civil Engineering Journal

基　　金：国家自然科学基金(51878548,52278214);陕西省自然科学基础研究计划重点基金(2022JZ-21);西部装配式建筑工业化协同创新中心科学研究计划(N202203);秦创原-未来城市建设与管理创新联合研究中心科研项目(YJZX20210008)。

摘　　要：疲劳断裂失效一直是导致钢结构桥梁发生破坏的重要原因之一。为了更好地利用断裂力学对此失效行为进行研究,开展桥梁钢板件标准疲劳裂纹扩展试验。利用金属磁记忆无损检测技术监测疲劳裂纹扩展行为,分析疲劳裂纹扩展过程中磁信号的变化情况。从理论及试验两方面探讨疲劳裂纹扩展长度磁信号量化方法,确定磁特征参数与裂纹扩展长度之间定量关系式。随后将所提关系应用于疲劳裂纹扩展剩余寿命预测确定性研究,并通过试验结果对其进行验证。最后考虑疲劳裂纹扩展的随机性及损伤信息更新的必要性,进一步开展疲劳可靠度评估研究。研究结果表明:磁信号梯度最大值可以较好地对裂纹扩展长度进行量化表征,剩余寿命预测结果与试验结果误差均在20%以内,基于磁信号的可靠性评估方法可以配合我们更好地制定桥梁维修及养护策略。Fatigue fracture failure has been one of the major causes of damage in steel bridges.In order to better investigate this failure behavior using fracture mechanics,standard fatigue crack growth tests on bridge steel plates were carried out.The fatigue crack growth behavior was monitored using metal magnetic memory nondestructive testing technique,and the variation of magnetic signal during fatigue crack growth was analyzed.The method of quantifying the magnetic signal of fatigue crack growth length was discussed from both theoretical and experimental aspects,and the quantitative relationship equation between magnetic characteristic parameters and crack growth length was determined.The proposed relationship was then applied to the deterministic study of fatigue crack growth remaining life prediction and verified by experimental results.Finally,considering the randomness of fatigue crack growth and the necessity of damage information update,fatigue reliability evaluation studies were further conducted.The results show that the maximum value of the magnetic signal gradient can quantitatively characterize the crack growth length well,the errors of the remaining life prediction results are within 20%of the experimental results,and the reliability evaluation method based on the magnetic signal can cooperate with us to better develop bridge repair and maintenance strategies.

关 键 词：疲劳裂纹扩展 金属磁记忆 断裂力学 疲劳寿命评估 可靠度分析 

分 类 号：U446[建筑科学—桥梁与隧道工程]