正交异性钢桥面板焊接接头疲劳性能提升方法及其评估

Methods and Evaluation of Fatigue Performance Improvement of Welded Joints of Orthotropic Steel Bridge Panels

为研究顶板厚度、熔透率和焊缝尺寸三种措施对接头疲劳性能是否有所提升,基于ANSYS-FRANC3D联合仿真方法,考虑不同荷载形式和不同裂纹扩展阶段的影响,从而综合评估三种措施对焊接接头疲劳性能的提升效果。研究得知:竖向荷载作用时,仅增加顶板厚度可以改善焊根处开裂情况,短裂纹阶段和长裂纹阶段随着顶板厚增加应力强度因子降幅分别可达30.57%和28.54%,同时也可改善多失效模式下焊根处疲劳开裂情况;水平荷载作用时,仅增加熔透率可改善焊根处疲劳开裂情况;相较于单一失效模式,短裂纹阶段和长裂纹阶段裂纹在多失效模式下,裂纹开裂机率分别提升7.58%和8.93%。

In order to investigate whether roof thickness,penetration rate and weld size can improve the fatigue performance of welded joints,based on the ANSYS-FRANC3D co-simulation method,the effects of different load forms and different crack growth stages were considered to comprehensively evaluate the effects of three measures on the fatigue performance of welded joints.The results show that under vertical load,only increasing the roof thickness can improve the cracking condition at the welding root;with increasing the roof thickness at short crack stage and long crack stage,the stress intensity factor decreases by 30.57%and 28.54%respectively;meanwhile,the fatigue cracking condition at the welding root under multiple failure modes can also be improved.Under horizontal load,the fatigue cracking at the welding root can be improved only by increasing the penetration rate.Compared with single failure mode,the crack cracking probability of short crack stage and long crack stage in the multiple failure mode is increased by 7.58%and 8.93%respectively.