正交异性钢桥面板横隔板及内隔板结构优化

Optimization of floorbeam and inner diaphragm on the rib-floorbeam oforthotropic steel deck

正交异性钢桥面板纵肋与横隔板连接处疲劳机理复杂,分析较为困难,针对这一问题,以横隔板弧形开口与U肋和横隔板焊缝端部周围区域为研究位置,结合区域内的应力分布规律,深入分析其受力机理,找出此区域内的疲劳易损点。以易损点构造细节的疲劳应力为控制指标,提出变厚度横隔板、双内隔板及横隔板与纵肋连接处反向圆弧切口等降低疲劳应力的构造形式,经过有限元计算,结果表明:变厚度横隔板和双内隔板分别对弧形开口处和焊缝端部的疲劳有明显的改善效果;反向圆弧切口可以使几何线性更加平顺,降低由于几何不连续导致的应力集中,可以显著降低上述两类疲劳细节的疲劳应力。

The fatigue mechanism at the connection between longitudinal ribs and diaphragm of orthogonal anisotropic steel bridge panel is complicated and difficult to analyze.In order to address this problem,the area around the curved opening of diaphragm and U-rib and the weld end of diaphragm is taken as the research location,and the stress distribution law in the area is combined with the in-depth analysis of the stress mechanism to find out the fatigue susceptibility point in this area.Taking the fatigue stress of the construction details as the control index,we propose the construction forms to reduce the fatigue stress such as variable thickness transverse spacer,double internal spacer and reverse arc notch at the connection between the transverse spacer and longitudinal ribs,etc.After the finite element calculations,the results show that:the variable thickness transverse spacer and the double internal spacer have an obvious effect on the fatigue at the arc openings and the end of the weld seam,respectively,the reverse arc notch makes the geometrical linearity smoother and reduces the stress concentration caused by geometrical discontinuities.Geometrical discontinuities,which can significantly reduce the fatigue stresses in the above two types of fatigue details.