Influence of geometric parameters on stress concentration factors of undermatched butt joint with single V-groove under three-point bending load

In order to improve the bending load-carrying capacity（BLCC） of undermatched butt joint under three-point bending load,the influence of joint geometric parameters on stress concentration factors（SCF） at the weld bottom center and the weld toe of undermatched butt joint with single V-groove are studied respectively based on the finite element method in this paper. Results show that the reinforcement height and the cover pass width play decisive role in the BLCC for undermatched butt joint. BLCC of undermatched butt joint can be improved by choosing the appropriate joint geometric parameters.