车轮位置对钢桥面板U肋对接焊缝的影响范围分析

Analysis on influence scope of wheel position on U-rib butt welds of the steel bridge deck

通过建立正交异性钢桥面板局部有限元模型,计算车轮荷载下U肋对接焊缝的主应力,提取各测点最不利横向位置下的纵向应力分布,得到纵向影响范围.基于各测点随荷载横向位置变化的应力,得到各测点的荷载横向影响范围,对比单轮单次荷载作用下的损伤度获得U肋对接焊缝的易损部位.结果表明:车轮荷载位置对U肋对接焊缝的纵向影响范围约2个横隔板间距;U肋对接焊缝靠近顶板部位横向影响范围约为900 mm,其他部位影响范围约为600 mm,可忽略"多车效应";U肋对接焊缝靠近顶板位置为U肋对接焊缝中的易损部位.

The local finite element model of orthotropic steel bridge deck is established. The principal stress of U-rib butt welds under single wheel is calculated. The longitudinal influence scope is obtained by the longitudinal stress distribution of measuring points under the most unfavorable transverse position. The transverse influence scope is obtained by the variation of stress amplitude with the change in transverse position. The vulnerable position of U-rib butt welds is determined by comparing the damage degree of four measuring points under a single loading of a single wheel. The results show that the longitudinal influence scope is about the distance between two diaphragms. The transverse influence scope of the position close to the deck is about 900 mm and others are about 600 mm, thus the multiple vehicles effect could be ignored. The position close to the deck is the most unfavorable in U-rib butt weld.