Where you can use this: Atlas Tube HSS Connections Hub onlyStatus: Beta · Region: US · Design codes: AISC 360-22, AISC Design Guide 39What this calculator does
Designs a moment connection between a wide-flange beam and a concrete-filled HSS column using a bolted extended end plate, in the four-bolt extended unstiffened configuration. Two design paths exist, and the calculator picks between them automatically.
Engineers often want a thinner end plate for cost or geometry reasons, but the standard thick-plate procedure does not cover it. Before this update, the thin-plate checks had to be done by hand or in a separate spreadsheet alongside the calculator, which created extra work and a risk of inconsistency between the two.
Inputting key properties
- Select the WF beam section and grade.
- Select the concrete-filled HSS column section, steel grade and concrete strength.
- Enter the end plate thickness. An End Plate Classification widget appears directly below this input showing whether the design is on the thick or thin plate path. A second flag in the End Plate Capacity section further down confirms thin end plate behaviour, so you can see which path you are on from either end of the sheet.
- Enter the threaded rod diameter, grade and layout.
- Enter the weld sizes.
Applying loads
Moment, shear and axial demand at the connection. On the thin plate path, shear is routed to the compression-side rods only, following the DG 39 SCO assumption, and a shear strength check for those rods appears under Threaded Rod Capacity. The tension-side rods are assumed not to carry shear.Reviewing the calculations
Thin plate path
Both paths
Column face and concrete-fill limit states, weld capacity and beam-side checks run as normal.Assumptions and exclusions
- Four-bolt extended unstiffened configuration only.
- The thin plate path activates automatically. It is not a manual toggle.