Several sub load cases per load group are a way to organize variations of a certain load group.
For example: assume the wind can blow from 4 directions. You could made 4 load groups Wind which you define as incompatible. One for each direction. But you could also define one load group Wind and organise the 4 directions using sub load cases. The main advantage of using sub load cases is that it’s faster to enter in Diamonds and that the list of combinations remains clear.
How to define sub load cases
- Add one load group for wind.
- Check the option Several load cases per group.
- Increase the number of load case to four. Diamonds will add Case 1, Case 2, Case 3 and Case 4 automatically to the list. You can change the name of the case if you’d like.
- The little guys define the incompatbility. When you click on the icon the little guys can hold hands or not.
- if they are not holding hands
, it means the sub load cases are incompatible. Meaning they cannot occur at the same time. This is particularly the case for wind/ snow loads. - if they are holding hands
, it means all sub load cases will act on the structure at the same time. This is particularly the case for dead loads.
- if they are not holding hands
It follows from the above text that it is also possible to use sub load cases for dead loads. This gives you a clear overview of the origin of each dead load. But the disadvantage is that each sub load case takes up memory leading to a longer calculation time. In view of the calculation time, we do not recommend using sub load cases for dead loads in medium to large models.
Let’s say a medium model, is a model with more than two floor levels.
How to remove sub load cases
- A load group containing sub load cases can be converted to regular incompatible load groups using the button Ungroup loadcases.
- To remove the load group completely from the list, select the load group and hit
. - To remove the sub load cases, but not the load group: set the number of sub load cases (= a.k.a. the number in the column #) to 1
- To remove the 3 columns #, Type and Name Load case:
- Make sure the column # contains the number 1 for all load groups.
- Uncheck the option Several load cases per group. The 3 columns #, Type and Name Load case will disappear.
