Weld group capacity (elastic method)

Calculate the capacity of a weld group using the elastic stress method

Input:

kip-ft
kips
kips
kip-ft
in
in
steel weld group

Output:

  1. Definitions
    • ϕw = Resistance factor for welds
    • Mu = Factored moment (kip*ft)
    • Nu = Axial load; Tension positive (kip)
    • Tu = Factored torsional moment (kip-ft)
    • Vu = Factored shear force (kip)
    • b = weld group width (in)
    • d = weld group depth, height, or diameter (in)
    • r = distance from centroid to weld, for calculating torsion stress (in)
    • fRu = resultant stress (kip / in)
  2. Calculate the geometric properties of the weld group
    • yc = d / 2 = 12 in
    • J = (b+d)3 / 6 = 7776 in3
    • Scx = bd + d2/3 = 480 in2
    • Aw = 2d + 2b = 72 in
    • rmax = Sqrt((b/2)2+(d/2)2) = 13.416 in
  3. Calculate the unit stress from each applied load
    • fPu = Nu/Aw = 0 kip / 72 in = 0 kip/in
    • fVu = Vu/Aw = 0 kip / 72 in = 0 kip/in
    • fMu = Mu/Sxx = 0 kip-in / 480 in2 = 0 kip/in
    • fTu,max = Tu rmax / J = 0 kip-in / 7776 in2 = 0 kip/in
  4. Calculate the peak resultant stress using vector combination
    • Note: fTu added to fVu (assumed to act in same direction)
    • fRu = sqrt([fTu + fMu]2 + [fVu + fTu]2 ) = 0
  5. Calculate the required weld size
    • Use weld with strength of 0 kip/in

Notes: