# Eccentric Shear Welded Connections

## Presentation on theme: "Eccentric Shear Welded Connections"— Presentation transcript:

Eccentric Shear Welded Connections
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

Elastic Vector Analysis
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. The actual weld thickness resisting shear and torsion forces is (0.707w), but for simplicity, we consider effective throat thickness = 1.0 inch. From direct shear only (due to P):- 1 inch Py Px P M=P·e W-30

Elastic Vector Analysis
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

Elastic Vector Analysis
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 =  w x 1 x (0.6 FEXX) W-32

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

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

Eccentric Shear Connection
Example (W-6) - Continued Select E70XX as given by matching table. Use ½ inch weld size W-35