Nominal Strength of WELD LRFD

Design strength of welds is taken as the lower of:

1)  PhiRe*Fw*Aw        PhiRe=0.75

2) PhiRe*Fbm*Abm

Minimum effective length of fillet welds:

Effective WELD length  not less 4 times the nominal size:  Lw>=4*w

Maximum WELD size for fillet welds:

w >= 1/8"  for Base material up to 1/4" thick

w >= 3/16" for base material 1/2 to 3/4" thick

w >= 5/16" for base material  over 3/4" thick

Maximum Weld Size for fillet welds:

a) Along edges of plate less than 1/4" thick. not greater than than the thickness of the plate.

if Base Plate < 1/4" then w=< 1/4"

b) Along edges of plate 1/4" or more in thickness, not greater than the thickness of the plate minus 1/16"

if Base Plate(BP) >=1/4"  then w=< (BP minus 1/16")

Notes

Effective cross-section of Weld area:

Aw (in²) = te*Lw  ;  te= 0.707 w,

te=Throat

w=weld size

Lw=weld Length, (inches)

Fw= Nominal strength of weld electrode (ksi)

Fbm= Nominal strength of base material (ksi)

Abm=Cross-sectional area of base material (in²)

BP=base plate thickness

PhiFe= 0.60  Resisrance factor-electrode-

(PCI  7ed  6.7.5.1)   (Fw=0.60*Fexx)

PhiRe= 0.75 Resistance factor -weld Group-

(LRFD factor Force, Ru=<0.75 Rn)