first of all, thanks for the quick response.
I’m actually interested to understand where the centre of gravity (or mass) is for the self-weight (input as a load case with factor 1.0) of a structure. The structure is a plated steel bridge with several stiffeners, diaphragms, openings etc.
As the bridge has varying sections (both in width and height) and is heavily asymmetrical, is essentially impossible to calculate the centre of gravity by hand.
One way around it would be to do some trial and error and model a single constraint to be moved around until the bridge is balanced, given the complexity of the model, this would take too much time and computational resources (each analysis would take approx 10 minutes to run).
In the export dialog from SofiPlus there is the option to calculate centre of mass and centre of rigidity, but I don’t know how to output the position.
Also, I assume that centre of mass and centre of rigidity would be calculated for the entire structure, while I would need it calculated for specified groups.