正交异性钢桥面板纵肋与顶板焊接细节疲劳性能评估

Evaluation on Welding Detail Fatigue Performance of Longitudinal Rib and Roof of Orthotropic Steel Bridge Deck

摘要:

钢桥面板中纵肋与顶板连接部位为最严重的疲劳控制细节之一。依靠双面焊新型焊接技术能有效避免传统单面焊焊根位置处“类裂纹”缺陷，从而达到提高连接焊缝疲劳抗力、改变疲劳开裂控制模式的目的。为评估纵肋与顶板双面焊疲劳抗力和疲劳寿命，对焊趾、焊根位置疲劳性能评估创新性地选用了等效结构应力法。研究结果表明：焊趾、焊根处的疲劳抗力性能可以通过等效结构应力法进行有效评估，同时具有网格不敏感性、计算效率高等系列优点；与传统单面焊相比，采用双面焊技术时外侧顶板焊趾已取代焊根位置作为疲劳开裂控制部位，其疲劳性能更加优异。

Abstract:

The junction of longitudinal rib and roof in steel bridge deck is one of the most serious fatigue control details. The use of new double-sided welding technology can effectively avoid the “crack like” defect in the traditional single-sided welding root position so as to achieve the purpose of improving the fatigue resistance of joint welds and changing the fatigue cracking control mode. To assess the double-side welding fatigue resistance and fatigue life of longitudinal rib and roof, the equivalent structural stress method is innovatively chosen to assess the fatigue performances at the position of welding toe and welding root. The results show that the equivalent structure stress method can be used to effectively assess the fatigue resistance at the position of welding toe and welding root， and has the advantages of grid insensitivity, high computational efficiency. Compared with the traditional single-sided welding， when the double-sided welding technology is adopted, the welding toe of the outer roof has replaced the welding root as the control part of fatigue cracking. Its fatigue performances are more excellent.