Exporting a subset of a model can help you save time when you need to investigate different variants of an analysis.
A user had a model with a number of different meshes with different mesh properties. He wanted to run an analysis on a subset of the entire components and after which, incrementally add more components to the analysis to understand the effects of these components on the baseline analysis.
He offered a solution whereby he wished to save successive copies as he added the additional components to the analysis. Thereby having for example a baseline analysis, then a copy with a baseline + subset1, then another copy with baseline + subset1 + subset2, and so on.
However every time he used the Save As to save the .prt and corresponding .fem & .sim he would get thefollowing error:
Siemens PLM experts Mark & Phil were able to determine there were two separate issues here, and thus two different solutions to the user's problem. First was that what the user really needed was to work with subsets and for this there was a specific capability in the Advanced Solver Options.
First to address the real issue:
There's another way to address this situation within the same FEM/SIM. However it depends on which version of NX you have and which solver you are using. NX supports subset exports of a model. [...] The idea here is that you have a FEM that has all of your meshes - no need to delete them. Then when you define a solution, you can select which parts of your model you wish to export with the Edit Advanced Solver Options, export options, subset export capability. If you control the subset export via groups containing meshes, then you have something that will be predictable as your model changes. If your meshes change, the groups will update to reflect the changes. You could create a group of meshes for a given solution, and use that group for the subset export for that solution.
The advanced solver options become a part of the solution definition. That means if you choose to export a portion of your model today, that same portion will be used tomorrow or later if you choose to re-solve. Other solutions can use the entire model or other groups.
The benefit to this is that you have a single FEM/SIM to manage. You will be able to quickly make post processing comparisons between models as you add components to it. The post views will use the SIM/FEM file information (mesh names, groups, load set names) within its UI. This only happens when the results from a post view are related to the work SIM file. For post views not related to the work SIM, the results are treated as if they are imported (no association to the SIM).
The downside is that it may not always be obvious what you are solving from a graphical point of view since you are solving a subset of the model. However, it is another way of working and shows a bit of flexibility in the product.
The attached document from Phil illustrates this neatly.
Then to address the users' perceived solution and it's issue:
The image above showed that:
b1.prt will be saved as beam1
b2.prt will be saved as beam2
beam_fem1.fem will be saved as beam1.fem
beam_sim1.fem will be saved as beam1.sim
NX only supports unique for all of its file types (PRT, FEM, SIM, AFM). You have beam1.prt, beam1.fem, beam1.sim. That's not allowed. The name (excluding the extension) has to be unique.
And here is a video that simply illustrates this.