Question: Can SCIA Engineer work in Viewer Mode if you don't have a license to use the software?

Answer: The torsional buckling coefficients ky and kz in SCIA are automatically calculated using two formulas separately for sway and non-sway frames. These formulas calculate torsional buckling coefficients that are greater (sway frames) or less (non-sway frames) than 1.

The concept of sway and non-sway frames is directly related to critical coefficients αcr in stability analysis.

• When αcr ≥ 10, the frame is non-sway, so the torsional buckling coefficients will be less than 1.
• When αcr < 10, the frame is sway, so the torsional buckling coefficients will be greater than 1.

Therefore, the user should perform a stability analysis before setting parameters for sway/non-sway frames to optimize the calculation of torsional buckling coefficients ky and kz for use in linear analysis.

• When αcr ≥ 10, the user can simply perform linear analysis by specifying, in the steel settings, behavior for non-sway frames for y-y and z-z directions, so that the formula for non-sway frames calculates torsional buckling coefficients for all elements.

• When αcr < 10, the user can choose to conduct linear analysis using buckling factors (which are always greater than 1). This method results in a much simpler analysis considering the second-order analysis that takes into account global and local imperfections. However, the user should carefully check whether this option is allowed in the applicable design code (e.g., the Belgian National Annex to Eurocode currently does not allow this method, requiring a second-order analysis). Also, note that this method is more conservative compared to second-order analysis when considering global and local imperfections.

It is also important to note that the formulas used in the calculation of ky and kz apply only in the case of rigid and/or semi-rigid frames. This limitation implies that the values of ky and kz calculated by SCIA should be checked when the case is different from the above.

In such cases, the user has several options available:

• Limitations in the calculated ky and kz can be set in the steel settings.