Panel-Zone Doubler-Plate Thickness (AISC 360 J10.6)
How thick a panel-zone doubler plate must be, sized by two limits.
Example
You enter
- Panel-zone shear demand Vu (kip) 300
- Column yield Fy (ksi) 50
- Column depth dc (in) 14
- Existing column web tw (in) 0.485
- Panel-zone depth dz (in, ~ beam depth between flanges) 22.64
- Panel-zone width wz (in, ~ column depth between flanges) 12.44
You get
- Bare web design strength phiRn 183 kip
- T strength (in) 0.308651
- T stability (in) 0.389778
- T plate (in) 0.4375
Details, formula, and sources
Strength t = (Vu - phiRn_bare) / (0.90 x 0.60 Fy dc); stability (Eq. J10-12) t >= (dz + wz)/90 for a plate not plug-welded to the web. On a stocky column with a small shortfall the stability minimum governs (a strength-only calc would spec a plate too thin to be stable); on a deep beam the strength governs. Reports the governing thickness rounded up to the next 1/16-in plate. A detailing aid, not a stamped connection design.
phiRn_bare = 0.90 x 0.60 Fy dc tw; t_strength = max(0, Vu - phiRn_bare) / (0.90 x 0.60 Fy dc); t_stability = (dz + wz)/90 (Eq. J10-12); t_required = max(t_strength, t_stability) when a doubler is needed.
The AISC 360-16 Section J10.6 panel-zone doubler-plate provisions, Eq. J10-9 and Eq. J10-12, by name.
AISC 360 is available through AISC; the J10.6 panel-zone and doubler-plate provisions are published design equations.
Estimate. AHJ and licensed professional govern.
Field names used by the API: required_shear_kip, fy_ksi, col_depth_dc_in, col_web_tw_in, pz_depth_dz_in, pz_width_wz_in, phi_rn_bare_kip, t_strength_in, t_stability_in, t_plate_in
- Two limits the doubler is the greater of the strength thickness (shortfall / 0.90 x 0.60 Fy dc) and the stability minimum (dz + wz)/90AISC 360-16 J10.6 / Eq. J10-12
- Not plug-welded Eq. J10-12 governs per plate unless the doubler is plug-welded to the web, when the combined thickness resists bucklingAISC 360-16 J10.6