Aiming at the S355 J2 W+N butt joint with a thickness of 12 mm plate

the influence law of geometrical parameters such as residual height H of weld seam and weld fusion width W of weld seam on stress concentration at weld toe was investigated by using finite element calculation method

and the empirical equation of stress concentration coefficient at weld toe was obtained by regression analysis. The results show that:both weld width and weld residual height have effects on the stress concentration factor H

but the variation of residual height has great effects on the stress concentration at the weld toe. Under the same weld width

the stress concentration coefficient Ktof weld toe increases with the increase of residual height

and the maximum increase is 33.19%. When 1.0 mm<H<2.0 mm

the effect of the increase of weld residual height on Ktincreases gradually

but when 2.0 mm<H<3.0 mm

the effect of the increase of weld residual height on Ktdecreases. Increase the width of weld seam and reduce the residual height of weld seam

which can alleviate the change of section shape at the welding toe and effectively improve the stress concentration at the welding toe.