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Stress and strain output for composite simulation

Hi,

I am facing a problem concerning the stress and strain output of a composites simulation. I have created a model of a thin rectancular composite with the laminate modeler and used extrude laminate to create a 3D structure.
In the laminate modeler I clicked request stress and strain output and in the solutions case control I enabled both stress and strain output.
As a result the post processor shows stress and strain values for all nodes on the outer surface but lacks all points within the structure.

Is there any way to generate the stress and strain values within the structure? So far I was unable to find an answer to my question in the help or the users guide. I am using NX 10.0 for this simulation.

Looking forward to your ideas. Thanks and best regards,

Elonora
8 REPLIES
Solution
Solution
Accepted by topic author Elonora
‎01-13-2016 06:04 AM

Re: Stress and strain output for composite simulation

Elonora,

 

By default NX Post shows results on free faces, this could be why you are not seeing the internal ply results.

 

In the Results tab, click Edit Post View. In the Display tab, change Display on from Free Faces to Volume. Then in the Edges and Faces tab, change Faces from Opaque to Translucent. You should be able to see all your results.

 

Regards,

 

Phil

 

 


Philippe Tremblay
phillippe.tremblay.ext@siemens.com
www.mayahtt.com

Re: Stress and strain output for composite simulation

Phil,
Thank you so much for your fast and detailed answer. I tried it just now but unfortunately nothing changed. If I change from volume to cutting plane there is a difference in what I see. Also I tried the command identify results using the translucent view and was able to get values for nodes of elements in the center of volume. Unfortunately the way you described didn't work for me even if it seemed exactly like what I was looking for.
Maybe there is another trick I haven't found yet?
Thanks again!

Re: Stress and strain output for composite simulation

Elonora,

 

Which results set are you post-processing? I was assuming you were looking at 'ply stress', as opposed to 'stress': how many plies are there, over how many element layers? If you want to see stresses on internal plies, you need to select the ply in the post navigator. Are there ply stress results for the internal plies?

 

The cutting plane option shows results on the cut plane and outside of that, on the free faces, so it should not work.

 

Phil


Philippe Tremblay
phillippe.tremblay.ext@siemens.com
www.mayahtt.com

Re: Stress and strain output for composite simulation

Elonora,

 

Are you using NX Nastran as your solver?

 

Phil


Philippe Tremblay
phillippe.tremblay.ext@siemens.com
www.mayahtt.com

Re: Stress and strain output for composite simulation

Hi Phil,

Yes I am looking at ply stresses. 'Stress' is only available if I use wedge elements of epoxy at a ply drop off. So in a model without ply drop offs as I am using now there is no 'stress' view at all.

I have 5 plies and in thickness direction I have one element per layer. That's what you get if you choose 'single ply per 3D layer' in the fill laminate or extrude laminate dialog box. I can see stresses for the internal plies for example ply 3 but only the 4 nodes of the total 8 (chexa8 element) that are situated on the free face of the model. The post processing view I get for internal plies for ply stress is like a ribbon around my object (2-dimensional).
With my earlier comment on the 'cutting plane' option I just wanted to explain, that NX does an action after I clicked it whereas it doesn't do anything if I click 'volume'. I know that this option is not going to help me getting the post processing view i want.

In my .fem I checked how many elements per ply I have and I have 400 elements per layer (10x40 Elements - rectangular) although I have difficulty seeing these elements too. Maybe it has something to do with the way I created the elements?
And yes I am working with the NX internal solver.

Thanks for your time and your support. I really appreciate it!

Regards,

Luisa

Re: Stress and strain output for composite simulation

Luisa,

 

You say:

 

'The post processing view I get for internal plies for ply stress is like a ribbon around my object (2-dimensional)'

 

I think that this is what I see on my 3D model internal  plies when using the default post view settings:

 

 

When I modify the settings as I described before:

 

and

 

 

I see this

 

and I am able to pick all the internal nodes for all the elements using Identify (I have to view from the top to pick top nodes, and from the bottom to pick bottom nodes.)

 

So if this does not work for you, I'm at a loss. Perhaps you can send me your model?

 

Regards,

 

Phil


Philippe Tremblay
phillippe.tremblay.ext@siemens.com
www.mayahtt.com

Re: Stress and strain output for composite simulation

Phil,

Thanks for the pictures you sent! You are completely right! I must have done something wrong yesterday. Today it works! I cannot thank you enough! I really appreciate the time and effort you put into helping me!
Thanks again!

Re: Stress and strain output for composite simulation

Hello

I have a problem with MSC Patran/ Nastran 2014
I would like to export the results of the tensor of element stress and the tensor of element strain in texts files after a modal analyses of a model of a thin rectancular composite but I didn't find how to export them, does anyone know how ?

 

Thanks and best regards,