Eccentric shear welded connection are popular for column

Eccentric shear welded connection are popular for column brackets supporting gantry crane loadings or mezzanine floors. The connection below produces (shear + torsion) on the weld. The LRFD method for (shear + torsion) is both difficult and lengthy, A more conservative “elastic vector analysis” method is allowed by AISC: W-29

The eccentric load is transferred to the “centroid” of the weld group. The transferred load shall consist of a load plus a moment (Mz = P·e), where: e = eccentrity. Py 1 inch P M=P·e Px The actual weld thickness resisting shear and torsion forces is (0. 707 w), but for simplicity, we consider effective throat thickness = 1. 0 inch. From direct shear only (due to P): - W-30

The transferred moment (M) causes additional shear stresses depending on the critical locations of the weld (far edges of the weld). where: M = moment due to eccentricity = (P. e) d = distance to far this weld point J = Polar moment of inertia. where: This can be vector analyzed to: W-31

Once these four stress components are evaluated for an extreme point of the weld. They can be added vectorially: Then the strength of 1 inch wide weld is evaluated as: Fv = 0. 707 w x 1 x (0. 6 FEXX) W-32

Example W-6 Determine the size of the weld required for the bracket shown. A-36 steel is used, SMAW process? Solution: W-33

Example (W-6) - Continued By inspection points (A $ B) are more critical than points (B & C); Take point (A): W-34

Example (W-6) - Continued Select E 70 XX as given by matching table. Use ½ inch weld size W-35