Effective Weld Length for HSS T, Y, and X Connections

The effective length of the perimeter weld around the branch member in axially loaded rectangular hollow structural section (HSS), T, and X connections is examined experimentally. By means of 16 full-scale connection tests, which were designed to be weld-critical, guidelines for the effectiveness of the heel, toe, and side welds are developed in terms of the principal connection parameters. It is found that more of the weld perimeter is effective for lower branch member to chord member angles, and more weld is effective for smaller width branch members (relative to the chord member size). The effective weld length recommendations advocated are shown to result in weld designs with an adequate level of safety, and revisions to some existing guidelines are proposed.