摘要
分别在江阴长江大桥1/4跨截面快车道、慢车道U肋对接焊缝处布设测点,测得该桥一天的应变历程曲线。基于雨流计数法以及Miner疲劳损伤累计准则,分析快、慢车道日损伤度分布规律,并提出了该桥U肋对接焊缝部位的日损伤分布模型,最后对U肋对接焊缝处的疲劳寿命进行评估。分析结果表明,快、慢车道出现损伤峰值的时间基本一致,但各峰值大小差异性较大,慢车道损伤峰值约为快车道损伤峰值的4.4倍;根据日损伤度分布模型得出的疲劳寿命拟合值与实测值吻合良好,可以应用于实际工程;大桥设计寿命约为慢车道U肋对接焊缝实测寿命的3.7倍,表明慢车道U肋对接焊缝的疲劳寿命远远不能满足设计要求,因此需要对慢车道U肋对接焊缝疲劳寿命给予特别关注。
The measuring points were set on the U-rib butt welds of fast lane and slow lane in a quarter-span of Jiangyin Yangtze River Bridge to measure the one-day strain process curves. The curves were filterred by MATLAB software to obtain the real strain process curves of steel box girder under the vehicle loading. The daily damage degree distribution rules of fast and slow lane were analyzed based on the rain flow method and Miner fatigue damage cumulative rule. The daily damage distribution model of U-rib butt welds was put forward and the fatigue life of U-rib butt welds was evaluated. The analysis result showed that the time when the damage peak of both kinds of lanes occurred was basically the same,yet the peak value differed a lot from each other. The peak value of the slow lane was 4. 4 times than that of the fast lane. The fitting value of fatigue life based on daily damage distribution model coincided well with that of the measured,which could be applied to practical engineerings. The design life of the bridge was superior to and 3. 7 times of the fatigue life of the U-rib butt in the slow lane,meaning that the fatigue life of the U-rib butt in the slow lane was far from demand,thus special attention should be paid to it.
出处
《工业建筑》
CSCD
北大核心
2016年第6期161-165,共5页
Industrial Construction
基金
国家自然科学基金面上项目(51478163)
高等学校博士学科点专项科研基金(20120094110009)
江苏省交通科学研究计划项目(2014Y02)
关键词
钢桥面板
U肋对接焊缝
应变历程
损伤度
疲劳寿命
steel bridge deck
U-rib butt weld
strain process
damage degree
fatigue life
