关键词: 桥梁工程；正交异性钢桥面板；弧形切口；残余应力；有限元分析

Abstract: To study the distribution characteristics of residual stress at welding holes and arc-shaped incisions of orthotropic steel bridge diaphragms, a three-dimensional finite element model of the weld joints of the roof, longitudinal ribs and transverse diaphragms was established. Based on the thermo-elastic-plastic finite element method, the numerical simulation of welding dynamic process was carried out, the dynamic change process of temperature field and stress field was analyzed, and the correctness of finite element calculation was verified by the measured data. The results show that the transverse residual stress is significantly affected by the initial residual stress of the roof and longitudinal rib weld within 20 mm of the weld seam distance from the arc starting end, and the farther the weld distance is from the initial fillet weld, the less the initial stress influences the residual stress. The residual stress amplitude of longitudinally ribbed diaphragm weld by indirect welding is small. The distribution trend of tangential stress at the measuring points of 0~180° in arc-cut conforms to the law of cosine function change in a period. Among them, the tangential stress at the measuring points parallel to the normal and longitudinal ribs is the largest. The variation of diaphragm thickness has no obvious effect on the residual stress of the welded hole position. The extreme values of residual stress and stress gradient at the through welding hole on the lower surface of top plate are located at the welding toe and welding root of the arc starting end of the diaphragm respectively. Without affecting the structural integrity of steel bridge panel, the radius of through welding hole can be increased to reduce the opening residual stress.

Key words: bridge engineering; orthotropic steel bridge panel; arc-shaped incision; residual stress; finite element analysis