焊趾几何形状对P355NL1钢焊接接头应力集中的影响

Effect of Weld Toe Geometry on Stress Concentration of P355NL1 Steel Welded Joint

应力集中是导致焊接钢结构发生疲劳断裂的重要因素。利用ABAQUS软件建立了P355NL1钢焊接接头有限元模型,并进行了应力计算,研究了焊趾处圆弧过渡半径r和焊趾倾角θ对应力集中系数K_t的影响;引入疲劳缺口系数K_f研究了焊趾几何形状对P355NL1钢焊接接头疲劳强度的影响。结果表明,θ相同时,K_t和K_f随r增大而减小;r相同时,K_t和K_f随着θ的增大而增大。增大焊趾处圆弧过渡半径或降低焊趾倾角都能提高对接接头的疲劳强度。

Stress concentration is a major factor leading to fatigue fracture of welded steel structure. The finite element model of P355NL1 steel welded joint was established and the stress was calculated by using ABAQUS software. The effects of weld toe fillet radius r and weld toe angle 0 on the stress concentration factor Kt were studied. The fatigue notch factor Kf was introduced and the influence of weld toe geometry on the fatigue strength of P355NL1 steel welded joint was studied. The results show that for the same weld toe angle 0, Kt and Kf decrease with the increase of weld toe fillet radius r, and for the same weld toe fillet radius r, Kt and Kf increase with the increase of weld toe angle 0. Increasing the fillet radius or decreasing the weld toe angle can improve the fatigue strength of the butt joint.