If you do not mind re-running the analysis to access the results then following files need to be retained for backing up and archiving the model data:
- SAP2000 - .SDB, .SBK, .$2K
- ETABS - .EDB, .EBK, .$ET
- SAFE - .FDB, .FBK, .$SF
- Perform3D
The data files for Perform3D are stored in a user-specified folder the the requisite files to access the model are as shown below. The folder named "DynaAnalysis" can be deleted.