Nonlinear Structural Analysis and Thermal Analysis create files using the same structure as CATIA V5. The analysis document is a .CATAnalysis file, the same file type that CATIA V5 creates for an analysis within the Generative Part Structural Analysis (GPS) workbench. The analysis document contains links to CATIA V5 part and assembly documents, the finite element model, and analysis properties.

In Nonlinear Structural Analysis and Thermal Analysis, the .CATAnalysis file contains additional analysis properties required to complete the nonlinear analysis. It also contains requests for output data for specified geometric areas and analysis steps. Finally, if the analysis has been run, the analysis document provides a link to the resulting output database (.odb) file.

Release information is also saved with the .CATAnalysis file. The release information allows the document to be upgraded when it is opened with future releases of Nonlinear Structural Analysis and Thermal Analysis. When you open an analysis document, the Nonlinear Structural Analysis or Thermal Analysis product checks the release information and does one of the following:

• If the document was saved using a previous release, the document is automatically upgraded to the current release.

• If the document was saved using a newer release, a message is displayed indicating that you cannot open this document.

The upgrade script can upgrade a document across multiple releases of CATIA. Every attempt is made to preserve the contents of the original document during the upgrade process. If you use Save to save the document with the original name, CATIA overwrites the contents of the original file. As a result, when the upgraded document opens, you should use Save As to save it with a new name until you are satisfied that the upgraded document is working properly.