Buckling length

Use the Buckling length tool to define and adjust buckling length factors for steel member design checks.

When you activate the tool, a tool palette opens.

Steel buckling length tool palette

The tool palette contains the main tools and parameter controls for assigning buckling settings.

Define – assign buckling length settings to selected bar elements.
Properties – view or edit buckling length settings of existing definitions. Opens the Default settings dialogue for selected buckling length definitions.
Reset – remove assigned buckling length settings from selected elements.
Set beta factor – apply user-defined beta factor values to selected elements.
Copy buckling lengths – copy buckling length settings from one element and apply them to others.
Automatic beta calculation – let the program calculate beta factors automatically based on model conditions.
Default settings – open default values used when you create new buckling length definitions.

Flexural buckling, stiff direction – define settings for flexural buckling about the stiff axis.
Flexural buckling, weak direction – define settings for flexural buckling about the weak axis.
Lateral torsional buckling, top flange – define lateral torsional buckling settings for the top flange.
Lateral torsional buckling, bottom flange – define lateral torsional buckling settings for the bottom flange.

Flex. buckling, stiff – enable or disable assignment of buckling settings in the stiff direction.
Flex. buckling, weak – enable or disable assignment of buckling settings in the weak direction.
LTB, top flange – enable or disable lateral torsional buckling settings for the top flange.
LTB, bottom flange – enable or disable lateral torsional buckling settings for the bottom flange.
For both flanges – apply the same lateral torsional buckling setting to both flanges.

beta – numeric field for the buckling length factor.
> – opens a small menu with predefined beta factors based on boundary conditions.

When you press Default settings, a dialogue window opens for configuring default buckling parameters.

Steel buckling length default settings dialogue

The dialogue contains the same beta input logic as the tool palette.

beta – default beta factor value for new buckling length definitions.
> – opens the same menu of predefined beta factors based on boundary conditions.
Sway – checkbox that controls whether sway conditions are considered in the default buckling setup.