In a fillet weld the effective throat (t) is the distance that carries shear stress across the weld. It is derived from the leg size (a) by the relation (t = 0.707a) for a 45Β° fillet, and it governs the strength of the weld group.
The nominal shear capacity of a continuous filletβweld group is proportional to the product of the ultimate tensile strength of the weld metal (F_u), the effective throat (t), and the total weld length (L). A commonly used empirical factor of 0.6 accounts for the average shear stress distribution and the reduction for multiβpass welds.
Design codes require the calculated capacity to be reduced by a safety factor and to be checked against the applied shear force. Proper selection of leg size, weld length, and weld material ensures that the weld group can safely transmit the required loads without excessive deformation or failure.
F_u = ultimate tensile strength of weld metal (MPa)
t = effective throat (mm)
L = total weld length (mm)
How do I calculate the effective throat of a fillet weld?
What is the empirical factor used in the nominal shear capacity formula?
How does the ultimate tensile strength of the weld metal affect its capacity?
What is the role of the total weld length in determining the shear capacity?
Can you provide an example calculation for the nominal shear capacity?
What is the significance of a 45Β° fillet in this calculation?
How does the empirical factor vary for different types of welds?
Results are for informational purposes only and do not constitute professional advice.
