The purpose of this paper is to develop an estimation formula of stress concentration
factors of butt-welded components under tensile loading. To investigate the influence of weld bead
profiles on stress concentration factors of double V groove butt-welded joints, butt-welded
specimens were made by CO2 gas metal arc welding. And the three main parameters, the toe radius,
flank angle and bead height were measured by a profile measuring equipment. By using the
measured data, the influence of three parameters on the stress concentration factors was investigated
by a finite element analysis. It is shown that the three parameters have similar effects on the stress
concentration factors. According to the simulation results, a formula to estimate the stress
concentration factors of butt-weld welded structures was proposed and the estimated concentration
factors from the formula were compared with the results obtained by the finite element analysis.
The two results are in a good agreement.