AISC LRFD 1.pdf

238 WELDS [Comm. J2.eners. The intensity of these out-of-plane stresses may be effectively limitedand cracking prevented if “breathing room” is provided by terminatingweb-to-flange welds. The unwelded distance should not exceed six times theweb thickness to assure that column buckling of the web within the unweldedlength does not occur.(e) For fillet welds which occur on opposite sides of a common plane, it is not possibleto deposit a weld continuously around the corner from one side to theother without causing a gouge in the corner of the parts joined; therefore thewelds must be interrupted at the corner. See Figure C-J2.9.4. Design StrengthThe strength of welds is governed by the strength of either the base material or thedeposited weld metal. Table J2.5 contains the resistance factors and nominal weldstrengths, as well as a number of limitations.It should be noted that in Table J2.5 the nominal strength of fillet welds is determinedfrom the effective throat area, whereas the strength of the connected parts isgoverned by their respective thicknesses. Figure C-J2.10 illustrates the shear planesfor fillet welds and base material:(a) Plane 1-1, in which the resistance is governed by the shear strength for materialA.Do Not Tie WeldsTogether HereFig. C-J2.9. Details for fillet welds which occur on opposite sides of a common plane.Fig. C-J2.10. Shear planes for fillet welds loaded in longitudinal shear.LRFD Specification for Structural Steel Buildings, December 27, 1999AMERICAN INSTITUTE OF STEEL CONSTRUCTION