AISC LRFD 1.pdf

236 WELDS [Comm. J2.in most cases. However, in certain cases, the disposition of welds affect the plannedfunction of connections, and notches may affect the static strength and/or the resistanceto crack initiation if cyclic loads of sufficient magnitude and frequency occur.For these cases, limitations are specified to assure desired performance.(a) At lapped joints where one part extends beyond the end or edge of the part towhich it is welded and if the parts are subject to calculated tensile stress at thestart of the overlap, it is important that the weld terminate a short distance fromthe stressed edge. For one typical example, the lap joint between the tee chordand the web members of a truss, the weld should not extend to the edge of thetee stem. See Figure C-J2.5. The best technique to avoid inadvertent notches atthis critical location is to strike the welding arc at a point slightly back from theedge and proceed with welding in the direction away from the edge. See FigureC-J2.6. On the other hand, where framing angles extend beyond the end of thebeam web to which they are welded, the free end of the beam web is subject tozero stress; thus, it is permissible for the fillet weld to extend continuouslyacross the top end, along the side and along the bottom end of the angle to theextreme end of the beam. See Figure C-J2.7.(b) For connections which are subject to maximum stress at the weld terminationFig. C-J2.5. Fillet welds near tension edges.Fig. C-J2.6. Suggested direction of welding travel to avoid notches.LRFD Specification for Structural Steel Buildings, December 27, 1999AMERICAN INSTITUTE OF STEEL CONSTRUCTION