If you only add a load case, you can simply reimport the FEM on the setup tab (there is a button that says “Reimport FEM”. None of the components or groups should be changed. You need to be really careful with this though. If you have made changes to the component setup in HyperSizer by reassigning elements to different components, you need to get these changes back into your nastran model before you try to reimport. If you reimport the nastran model with the original component layout, then HyperSizer will go back to the original component layout and you will lose your changes.
Phil
Topic: How do you add a load case without losing component and group definitions? (Read 27965 times)