When opening Nastran In CAD for the first time you might be a bit confused about the model tree.  There are so many diffetent options and some are the same and and and….

In this blog I will try and demystify it a little for you.

There are two main sections that we will be focusing on.  The Part section and the Model section.  In the Part section you will be able to create separate analysis for the assembly or part.

In each Analysis you will find the following properties which can be changed for that specific analysis. It will also have in brackets and in red what type of analysis you are performing (linear static etc)

Units – Utilise the model units of measure or change them to the following of SI,modified SI,English or CGS.

Nodes and Elements will update as you generate your mesh and inform you as to the count in the model.  The more elements and nodes you have the more calculation time you will have.

The next section will detail what parts and assemblies are partaking in the analysis.

The idealizations section details what type of elements you have in the analysis.  You can have multiple parts be in the same idealization.  eg. small pin and large pin are part of solid 1 and cast lever is part of solid 2 in the above image.  It will also identify the colour of the objects when they are meshed and the material assigned to it.

Mesh model will show any additional mesh controls.  This is where you will refine only a portion of the model to get a better convergence in tight spots.

The last portion is the Subcases.  Here you will find the different loads and constraints applied to the model as well as the results when you have run the analysis.