WT Braces Mar 2020

In the petrochemical business, it is quite common to see structural steel braces built from WT shapes.

If you like Table 4-12 in the AISC 15th Edition, then you might like the attached example plots which I built on the same principle.

AISC 15th Edition LRFD maximum axial capacities in kips; KL in feet

Maximum axial capacities are tabulated for KL/rx <= 200 and KL/ry <= 200

Fy = 50 ksi

Conventional plate thicknesses = [0.25, 0.375, 0.5, 0.625, 0.75, 0.875, 1, 1.25, 1.5, 1.75, 2]

Gusset thickness and eccentricities are similar to AISC 15th Edition Table 4-12 for single angles
Gusset plate thickness = next larger conventional thickness plate, given 1.5 X tf_detail
   Example for WT4x12:
      Therefore, tf_detail = 0.375”
      Therefore, t_gusset_theoretical = 1.5 x tf_detail
         t_gusset_theoretical = 1.5 x 0.375”
         t_gusset_theoretical = 0.5625”
         t_gusset_used = 0.625” (next largest conventional)
   Example for WT4x12:
      Therefore, eccentricity = t_gusset/2
      Therefore, eccentricity is ≥ 0.75 x tf_detail
         eccentricity = t_gusset/2
         eccentricity = 0.625”/2
         eccentricity = 0.3125”

Included self-weight in the moment (assuming members might be horizontal)
  No fireproofing weight
Included amplification factor to P delta moment

Link to my single angle brace calculations