Groove Weld Length for an Applied Load

ScopeL = load / (stress in ksi x 1000 x throat), with stress in ksi = 0.30 FEXX (ASD) or 0.75 x 0.60 FEXX (LRFD) for a PJP weld; a CJP weld's shear is base metal, the smaller of 0.60 Fy and 0.60 Fu with their factors. A 100,000 lb LRFD load on a 0.25 in E70 PJP throat needs about 12.7 in. Round up, split between joint sides, and add for returns and minimum-length rules. AWS D1.1 / AISC 360 §J2; the WPS and engineer of record govern.

Formula or tablerequired_length = applied_load / (stress_ksi x 1000 x throat), the inverse of capacity = stress_ksi x 1000 x throat x length; PJP: stress_ksi = 0.30*FEXX (ASD) or 0.75*0.60*FEXX (LRFD) on the WPS effective throat; CJP: stress_ksi = min(0.60 Fy/1.50, 0.60 Fu/2.00) (ASD) or min(1.00 x 0.60 Fy, 0.75 x 0.60 Fu) (LRFD), base metal on the thinner part thickness.

Source and editionGroove weld (CJP / PJP) shear capacity (AISC 360 Table J2.5 weld-metal shear 0.60*FEXX on the effective throat for PJP; CJP shear is base metal per Table J2.5), solved for the length, per AWS D1.1 Structural Welding Code and AISC 360 §J2, by name.

Free accessFirst-principles AISC J2 shear. A CJP weld with matching filler develops the base metal in tension/compression; the PJP effective throat is read off the qualified WPS. The WPS, weld inspector, and engineer of record govern.

What governsEstimate. AHJ and licensed structural engineer govern.

API field namesapplied_load_lb, weld_type, effective_throat_in, electrode, method, required_length_in, stress_ksi

• Effective throat CJP uses the thinner part thickness; PJP uses the WPS effective throat (groove depth less the AWS Table 3.1 reduction); user-suppliedAWS D1.1 Table 3.1
• Round up and detail round the length up, split between joint sides, add for returns and minimum-length rulesAWS D1.1