正交异性板疲劳分析及构造细节改进设想

针对正交异性钢桥面板疲劳开裂的普遍现象,对正交异性钢桥面板疲劳构造细节进行分析,重点讨论了几种典型的疲劳裂纹易发生部位及其失效模式.根据现场实测轴载谱,利用有限元软件对某实桥典型疲劳细节的疲劳寿命进行了计算.分析结果表明:按照国外规范计算,该桥疲劳验算点寿命能够满足要求,但是按照该桥实测轴载进行疲劳验算,纵肋对接焊缝、纵肋与顶板焊缝细节则均不能够满足要求.为提高正交异形板抗疲劳性能,需减少焊缝或提高焊缝抗力,并提出了两种新的构造细节的改进设想.

Fatigue analysis of orthotropic steel bridge deck and improvement of ideas of structural details

Fatigue cracking in orthotropic steel bridge has become a common phenomenon.Fatigue details of orthotropic steel panel were analyzed,and several typical fatigue cracks and its failure mode were discussed.According to field measurement axle load spectrum,the fatigue life of a typical real bridge fatigue details was calculated based on finite element analysis and simulation.The result show that,the fatigue life of fatigue checking point of the bridge meets the requirements according to foreign standards,however,when calculating the life using field measurement axle load spectrum,fatigue life of both longitudinal ribs butt welds and longitudinal ribs and roof weld are not able to meet the requirements.In order to improve the fatigue performance of orthotropic steel bridge beck,we need to reduce the weld or improve weld resistance.Two new ideas of improvement for the structural details are proposed.