Working with load groups in structural analysis software
After you’ve finished modelling your structure you will want to apply loads to it. Most of the time you will want to group these loads together for a particular purpose to make your load combinations simpler. There is no way to add load groups, they are created at the same time as you add a load. S3D automatically names these as LGX where X = a positive number, however you can name these anything. For example: I would like to to apply a wind load to my structure, so I will name the load group W.
After you’ve added all your loads and assigned them to the load groups you want, if you want to design your structure according to a design code, you’ll need to apply appropriate load combinations (applying load combinations). Once you’ve completed this step, you can assign your load groups to load cases as per the design code load combinations.