Designing Multi-Orientation Fillet Welds

Here is an example on how to apply the strength reduction factor, M_w for multi-orientation fillet welds.

In the weld configuration shown in Figure 1, 8-millimetre fillet welds are used, X_u = 490 MPa and the plate is G40.21 350W steel. Note that the farside plate is thicker.

In accordance with CSA S16-14 Clause 13.13.2.2:

               V_r = 0.67 ɸ_w A_w X_u (1.00 + 0.50 sin^1.5 θ) M_w

where:

θ = angle of axis of weld segment with respect to the line of action of the applied force
M_w = strength reduction factor for multi-orientation fillet welds

a) Weld segment at θ = 60^o:

Orientation of the weld segment under consideration: θ₁ = 60^o
Orientation of the weld segment in the joint that is nearest to 90^o: θ₂ = θ₁ = 60^o

b) Longitudinal weld segments (θ= 0^o):

Orientation of the weld segment under consideration: θ₁ = 0^o
Orientation of the weld segment in the joint that is nearest to 90^o: θ₂ = 60^o

c) Weld group resistance:

V_r = 2 x 0.67 x 0.67 x 8 x 100 x 0.707 x 0.490 (1.00 + 0.50 sin^1.5 0^o) 0.895 + 0.67 x 0.67 x 8 x 120 x 0.707 x 0.490 (1.00 + 0.50 sin^1.5 60^o) 1.00
= 2 x 111 + 209 = 431 kN

For this application, the base metal resistance need not be checked.