NX and NASTRAN, different result with IGS import or NX part

[mitchellmarine]

Dear all,


I've posted on UG/NX forum but it's probably more appropriate here, sorry for double posting

I'm quite new with NX/NASTRAN(7.5) package but I have a small FEA background.

I'm doing some practical testing to learn how to use NX with NASTRAN.

I'm getting bogged on a simple I beam made with 2D shell elements.

Simulation is quite simple : I beam with pivot ends and tranversal force. It's just bending !

When I draw my beam with an other CAD software(Rhino) and import IGES in NX simulation, everything run ok, hand calculation give same result.

But when I draw my beam with NX (I tried everything in a part or assembly, same result), with the same way of preprocessing, result are stranges with different stress on top or bottom (near 20% difference!).

http://files.engineering.com/getfil...-c15445a4fe03&file=nx_beam_2D_element.JPG

Thanks for your help

Regards

Mitch

 

[ZeroExperience]

On MSC Nastran, there is a .dat or .bdf that contains all the model details.

On NX Nastran, I would compare the two files that contain all the model details from the two methods you mentioned. I don't know what file types they are since it is NX Nastran and I am a MSC Nastran user.

If you would like, you can post your files here and I can skim them to note any differences.