考虑微动疲劳的斜拉桥钢绞线斜拉索时变可靠性分析  

Time-dependent reliability analysis of strand cables of cable-stayed bridges considering fretting-fatigue factor

作　　者：刘沐宇[1] 陈齐风[1] 吴志强[1] 

机构地区：[1]武汉理工大学道路桥梁与结构工程湖北省重点实验室,湖北武汉430070

出　　处：《土木工程学报》2012年第7期141-147,共7页China Civil Engineering Journal

基　　金：武汉市科技攻关项目(201160923308);高校博士点科研专项基金(博导类)(20110143110016)

摘　　要：腐蚀与微动疲劳是钢绞线斜拉索退化的主要原因,与平行钢丝索相比,钢绞线斜拉索钢丝之间的相互作用力大,微动疲劳作用明显。基于时变可靠性理论,利用有限元软件ANSYS建立钢绞线钢丝接触模型求解钢丝之间的相互作用力,以此给出微动疲劳随时间发展的表达式,构造了钢绞线斜拉索抗力退化函数,进而建立同时考虑腐蚀与微动疲劳的钢绞线斜拉索时变可靠性模型。计算结果表明,以可靠指标β=4.7作为结构失效标准,与不考虑微动疲劳的钢绞线斜拉索相比,考虑微动疲劳的钢绞线斜拉索可靠性下降速度加快,寿命缩短6.3年。研究结果对探明钢绞线斜拉索退化机理,评估其使用寿命具有比较重要的理论与实际意义。Corrosion and fretting-fatigue are main causes of cable degradation. Comparing with the parallel wire cable, the interaction force between the wires in strand cable is large and the fretting-fatigue effect is obvious. Based on the time-dependent reliability theory, using the ANSYS software, a strand wire connection model is set up and solve for the interaction force between the wires, then a fretting-fatigue time varying function is established for time-dependent reliability analysis considering both corrosion and fretting-fatigue. The results show, taking a reliability index of β =4.7 as the structure failure criterion, comparing with the model considering only corrosion, the reliability index β decreases for the model considering with both factors considered, and the life span is cut by 6.3 years.

关 键 词：斜拉桥 钢绞线斜拉索 微动疲劳 腐蚀 时变可靠性 

分 类 号：U443.38[建筑科学—桥梁与隧道工程]