Fatigue-related corrosion is a complex phenomenon that induces damage accumulation and electrochemical deterioration throughout the service life of the structure. This article presents a previously proposed and modified strain-life Smith–Watson–Topper corrosion model for details on fillet-welded connection of highway sign support structures. To evaluate the degree of corrosion activity, hot-dip galvanized, weathering, and low-carbon steel are investigated with respect to chemical compositions, material properties, and the corresponding corrosion resistance indices. The existing fatigue testing data were analyzed and used to evaluate fatigue resistance under various corrosion environments. A modified Smith–Watson–Topper corrosion model is further utilized to determine acceptable constant amplitude fatigue thresholds for the American Association of State Highway and Transportation Officials fatigue limits under each corrosion category. It was found that low constant amplitude fatigue threshold values were observed for ASTM A588, A595, and A572 steels in locations with corrosion categories exposed to severe corrosive environments. Under these conditions, hot-dip galvanization or other surface treatments of the steel components of the sign supports are recommended to achieve higher constant amplitude fatigue threshold values.

中文翻译：

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应变-寿命疲劳-腐蚀模型在标志支撑结构角焊缝连接中的应用

与疲劳相关的腐蚀是一种复杂的现象，会在结构的整个使用寿命期间引起损伤积累和电化学劣化。本文介绍了先前提出和修改的应变寿命 Smith-Watson-Topper 腐蚀模型，用于详细说明公路标志支撑结构的角焊连接。为了评估腐蚀活动的程度，研究了热镀锌钢、耐候钢和低碳钢的化学成分、材料性能和相应的耐腐蚀性指数。对现有的疲劳试验数据进行了分析，用于评估各种腐蚀环境下的疲劳抗力。进一步利用修改后的 Smith-Watson-Topper 腐蚀模型来确定美国国家公路和运输官员协会在每个腐蚀类别下的疲劳极限可接受的恒定振幅疲劳阈值。结果表明，ASTM A588、A595 和 A572 钢在腐蚀类别暴露于严重腐蚀环境的位置中观察到较低的恒定振幅疲劳阈值。在这些条件下，建议对标志支架的钢部件进行热浸镀锌或其他表面处理，以实现更高的恒定振幅疲劳阈值。和 A572 钢在腐蚀类别暴露于严重腐蚀环境的位置。在这些条件下，建议对标志支架的钢部件进行热浸镀锌或其他表面处理，以实现更高的恒定振幅疲劳阈值。和 A572 钢在腐蚀类别暴露于严重腐蚀环境的位置。在这些条件下，建议对标志支架的钢部件进行热浸镀锌或其他表面处理，以实现更高的恒定振幅疲劳阈值。