OK, try using...
Insert -> Combine -> Join Faces...
...and first try the 'On Same Surface' option. If that doesn't do it you could try using the 'Convert to B-Surface' option but looking at your model, I'm not sure that either option will give you what you want. I say this because those small faces, at least the faces that I think you're talking about, are part of blends and if this model was created using NX then you've already got the simplest model possible. Now if this model was created in some other system and then imported into NX, then perhaps the above workflow will get you some improvement but again I would not expect this to remove ALL the so-called 'small surfaces'.
If this file come from other CAD system, consider also the opportunity to have a better output... ask NX to solve geometric problems is harder than solve them in the native system.
if you don't have access to the original CAD Part, you can also evaluate:
- Simplify Option (Step)
- Optimize Option (Step)
- File / Export /Heal Geometry
before manually do something.
I'm working en 2D axisymmetry, the plan is composed by severals parts and I can not merge the neigbour parts. The idea is to merge all the parts by the edge between them then to mesh them with differents mesh densities.
But, I don't know how I can to do it ?
Join face worked for me even on step input. Just note that there is no confirmation of the action but as soon as you select the solid, all the faces with edges merge.