A butt weld is set on the cross section of an I-shaped beam. There are bending moment M and shear force V at the splicing position, where M=1120 kN·m and V = 374 kN. The beam is made of Q355b steel and semi-automatic weld is used with welding rod E50. The design value of the weld tensile strength fwt is 260 N/mm 2 . Please check whether the strength of the butt weld is safe by calculation.