索承式桥梁吊索钢丝腐蚀疲劳寿命评估

根据吊索镀锌钢丝腐蚀疲劳破坏特点，把镀锌钢丝腐蚀疲劳纹形成和扩展过程分解成镀锌层腐蚀失效、蚀坑萌生、蚀坑形成、短裂纹扩展、长裂纹扩展和断裂破坏等阶段，建立各阶段时间表达式，得到镀锌钢丝疲劳寿命表达式，提出基于断裂力学的吊索钢丝腐蚀疲劳寿命评估研究结果方法。通过算例分析复杂运营条件下腐蚀环境和应力幅等因素对吊索钢丝腐蚀疲劳寿命的影响，研究结果表明：吊索钢丝腐蚀疲劳寿命主要由钢丝镀锌层腐蚀、蚀坑发展和短裂纹扩展等3个阶段组成，为了准确地评估吊索腐蚀疲劳寿命，需要掌握大桥的运营环境和交通荷载。

Evaluation of corrosion fatigue life for corroded wire for cable-supported bridge

According to the fatigue damage characteristics of galvanized wire, the propagation process is decomposed into 7 stages, including galvanized layer failure, matrix corrosion pit initiation, short crack propagation, long crack propagation and fracture damage stage. Then the expression of time in different stages and the galvanized wire fatigue life expression is established, and the evaluation method of corrosion fatigue is putted forward based on fracture mechanics. Finally through the case analysis of complex factors such as operation under the condition of corrosion environment and stress amplitude, the impact on the wire corrosion fatigue life is analyzed. The results show that the corrosion fatigue life of wire is mainly composed of steel galvanizing layer corrosion, pit development and short crack extension, and in order to accurately assess the corrosion fatigue life of wire, the operating environment and traffic load need to be grasped.