Automatic beta factor calculation

FEM-Design 18 can automatically calculate beta buckling factors. When calculating buckling factors, the program considers:

  • stiffness of connecting bars,
  • bar's end conditions,
  • supports,
  • whether the bar is sway or not.


  • In case here is no connecting bar to the calculated column or beam, but there is a connecting plate or wall, then the shell’s stiffness is considered in beta calculation.
  • Automatic buckling length calculation is a macro feature therefore, once beta factor is calculated and the structure is modified afterward, beta factor will not be changed automatically.


Improved lateral torsional buckling

LTB for top and bottom flange

It is now possible to define different lateral torsional buckling lengths for top and bottom flanges of steel bars. Checking For both flanges option in the tool window makes it possible to use the same buckling lengths for both flanges.


Due to this modification, lateral torsional check is now carried out independently for top and bottom flange of a bar.


Continuously restrained option

Continuously restrained option is now available for Lateral torsion buckling.


Updated Load position for general method icons refer to the fact that the same load position option has different effect on top and bottom flanges. For example, in case of top flange and top load position, the load has a destabilizing effect, while in case of bottom flange and top position, the load has a stabilizing effect.

Other buckling lengths improvements

Two new options are now available for buckling lengths of RC, steel and timber bars.

Set beta factor

It is now possible to can set the same beta factor for more types of buckling lengths.


Copy buckling length

It is now possible to copy all selected types of buckling lengths from one bar to another.


  1. Select the types to copy.
  2. Select the source bar.
  3. Select the destination bar.


Steel fire design improvements

Member surface emissivity and Adaptation factor have some additional value options in the side menu.


Steel joint utilization summary

Check the Show summary option in Steel Joint module in order to get an overview of all checks performed on a joint.


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