Westok cellular beams
Composite and non-composite steel beams with Fabrication type set to Westok cellular can be designed or checked to Eurocodes and BS5950.
If working to any other design code the Westok cellular fabrication type can still be selected, but if design is attempted, the beam status will be reported as 'Beyond Scope'.
Automatic design in Tekla Structural Designer
Select Autodesign in the Properties window to have the program select a suitable top and bottom section from the specified Design section order and configure the cells automatically.
To control the autodesign parameters, go to the Westok page of the Properties dialog box.
On this page, your selection of beam type and beam location controls which of the beam depth, cell diameter and pitch options are available, as indicated in the table below:
| Beam type | Beam Depth | Cell Diameter | Cell Pitch |
| Floor, primary |
Automate Maximum depth |
Automate Minimum diameter Fixed diameter# |
Automate Fixed pitch# |
| Floor, secondary |
Automate Maximum depth Fixed depth |
Automate Minimum diameter Fixed diameter# |
Automate Fixed pitch# |
| Roof, primary |
Automate Maximum depth |
Automate | Automate |
| Roof, secondary |
Automate Maximum depth |
Automate | Automate |
Note that the entries marked # must be selected together i.e. Fixed Diameter and Fixed Pitch is OK but Fixed Diameter and Automate Pitch is NOT OK. In addition, a range check is provided in order to stop inappropriate combinations of Fixed diameter and pitch. The range check is,
- The pitch must be in the range 1.3 to 1.8 times the cell diameter and the minimum web post
width = S – Do ≥ 130 mm
Where:
Do = the cell diameter
S = the cell pitch
The distance to first cell, S1 option allows you to fix the distance to the first cell or allow the program to calculate it.
The following table provides the mix of sections that are trialed for each beam type,
| Beam type | UB/UB - symmetric | UB/UB - asymmetric | UB/UC | UC/UC |
| Floor, primary | Yes | No | Yes | Yes |
| Floor, secondary | Yes | Yes | Yes | Yes |
| Roof, primary | Yes | Yes# | No | No |
| Roof, secondary | Yes | No | No | No |
The general rule is that for the allowable mix of sections, the combination of sections returned from the Automate process is that which provides the lowest combined weight. The UB/UC and UC/UC mix of sections for floor beams is only attempted if the depth of the beam is set to Fixed or Maximum. Also, the mix of sections marked with # is only attempted if the lateral torsional buckling utilization ratio (U/R) is ≥ 1.25 times any other U/R. In this case in contrast to all others, it is the bottom tee that is reduced back down the order file.
Manual design in Tekla Structural Designer
Unselect Autodesign in the Properties window if you want to manually select the top and bottom sections from the Selection Section dialog.
If the combination of top and bottom sections that you require is not listed you can click Add... to specify the sections you require.
To control the beam depth and cell configuration, go to the Westok page of the Properties dialog box.
The resulting cell configuration is confirmed on the Westok openings page of the dialog.
Export to Cellbeam for design
As an alternative to designing your Westok cellular beams directly in Tekla Structural Designer, if you have access to the Westok Cellbeam software you can export selected beams to that instead. Once designed they can then be re-imported back to the Tekla Structural Designer model.
For further details, see: Export to and import from Westok Cellbeam