桥梁钢结构疲劳设计原则及方法

Fatigue Design Principles and Methods of Bridge Steel Structures

为降低钢箱梁横隔板开口边缘处的疲劳应力,建立大桥主桥钢箱梁的有限元模型,计算轮载作用下此处的疲劳应力幅。采用累积损伤法评估结构的疲劳性能,预测其疲劳寿命。原设计方案未能满足重载交通量日益增加时的疲劳寿命要求,因此本文提出两种有效减小疲劳细节5处疲劳应力幅的方法:增加上横隔板厚度;距离原横隔板0.3 m处增加一道小横隔。结果表明,增加上横隔板厚度及原横隔板增设小横隔板的方法在理论和实践中均具有可行性,对正交异性钢桥面板抗疲劳设计具有参考意义。

In order to reduce the fatigue stress at the open edge of the transverse partition of the steel box girder,a finite element model of the steel box girder of the main bridge was established to calculate the fatigue stress amplitude here under the action of wheel load.Cumulative damage method was used to evaluate the fatigue performance of the structure and predict its fatigue life.The original design can not meet the requirements of fatigue life when the heavy traffic volume is increasing,so this paper puts forward two effective methods to reduce the fatigue stress amplitude at 5 fatigue details:increase the thickness of the upper transverse partition,and add a small transverse septum 0.3 m from the original transverse septum.The results show that the method of increasing the thickness of the upper transverse partition and adding small transverse partition to the original transverse partition is feasible both in theory and in practice,and has reference significance for the anti-fatigue design of orthotropic steel bridge panels.