I think there may be a problem in the analysis of columns. The calculations do not seem to consider lateral restraints in determining the effective length of the column.
To simplify my query, I have modelled two structures between which there is only one difference:
the columns are continuous in one structure and spliced in the other.
The continuous columns fail on buckling and the spliced columns do not. Please refer to attachment.
First of all. Please read the background information on how the steel check according to the Eurocode is implemented. Go to tab “Settings & Manual” and choose “Manual”. Go to chapter “Background : Buckling”
Note that lateral supports are not considered automatically.
Why?
There is no way to check if attaching beams will act as lateral supports or not. Meaning. Can the lateral forces be absorbed or not. Is there a bracing or not.
Anyway. The user / engineer will always has to input the lateral supports himself.
How?
Open the beam/column dialog. Go to tab Eurocode. Here you can enter the lateral supports. Please read the manual as well on this part.
To visualize these supports, switch on “Beam Groups”.