车轮荷载下钢箱梁疲劳构造细节应力等级评定

针对车轮荷载作用下钢箱梁的疲劳构造细节等级评定问题，基于应力影响线，研究钢箱梁9种疲劳构造细节的局部疲劳应力。根据等效损伤原理对最大应力幅进行修正，并以此为依据划分钢箱梁疲劳构造细节。结果表明：车轮荷载对钢箱梁9种疲劳构造细节的应力影响范围均较小，横隔板与顶板、纵肋相交处的应力影响范围为横隔板间距；顶板与纵肋相交处、纵肋对接处以及顶板对接处，应力影响范围为横隔板间距的1/2。钢箱梁横隔板与纵肋相交处的修正等效应力幅最大，纵肋对接处的修正等效应力幅最小。考虑受力和施工质量，钢箱梁疲劳构造细节可划分为5个疲劳应力等级，并给出9种疲劳构造细节对应的等级。

Fatigue stress level evaluation of structural details of steel box girder under wheel load

In order to evaluate the fatigue stress level of the structural details of a steel box girder under the wheel load, the local fatigue stress of nine structural details were studied based on the stress influence line. The greatest stress amplitude was corrected according to the principle of damage equivalence, and the structural details of the steel box girder were divided. The results show that the vehicle load has little influence on the fatigue stress of the nine structural details of the steel box girder. At the intersection of the diaphragm plate, the roof, and the longitudinal rib, the influence on the stress occurred in the interval of the diaphragm plate. At the intersection of the diaphragm plate and the longitudinal rib, and at longitudinal rib joints and roof joints, the influence on the stress occurred at half of the interval of the diaphragm plate. The corrected equivalent stress amplitude was the greatest at the joint of the diaphragm plate and the longitudinal rib, and the smallest at longitudinal rib joints. With consideration of stress and construction quality, the fatigue stress of the structural details of the steel box girder can be classified into five levels, and the corresponding levels of the nine fatigue structural details are also provided.