Learning Forum

[MichaelDelle]

 Greetings,

I am brand new to the Ansys software and I have a project where I need to model both a 2D and a 3D model of an aluminium honeycomb sandwich panel and test how mechanical loading and thermal loading affect the properties of the composite.

I have found the Honeycomb extension on Ansys but I dont know how to model the 2 faces as solid models instead of a surface body. I dont understand how I can make the entire sandwich panel in 2D though. In 3D it seems much easier since I can just make the 3 components in Solidworks and through an assembly using mates I can just make the final 3d model. 

Is there a specific tool that I need to use in order to make the 2D model ? How should I proceed ? I know I could always do 3 solid bodies on Ansys and specify through material selection that the middle body is of a honeycomb ply type and just add the properties of the aluminium alloy I will be using. 

Please let me know and thank you for your time.

Michael

[peteroznewman]

Read some of the 323 results that Google returns when searching for the word honeycomb on this site to get a feeling for the different approaches available.

[MichaelDelle]

Thank you Peteroznewman for your reply.
I have thought about it and I think if I need to make a 2D honeycomb sandwich panel I could use ACP since from my understanding, you can utilize shell elements there.
Do you have any alternatives that maybe I should look at Ansys ?
Thank you

[peteroznewman]

Only use ACP if you have a composite layup.

Don't use ACP if you want to just use shell elements with an isotropic material.

Shell elements are 3D. I think ACP is also only 3D, but I am not sure.

What type of honeycomb core do you have? It is usually orthotropic, which means 2D is not appropriate, you will have to do a 3D model.

[MichaelDelle]

Thank you for your reply Peter.
Well for the 3D model yes indeed it will be an orthotropic sandwich panel with a honeycomb in the middle which I managed to model in Solidworks.
However, the whole thing of my project is to try and figure out if I could acquire similar results with a model that is only 2D thus reducing the computational needs of the analysis and then discuss the differences.
I have seen some tutorials that explain how to operate in 2D only in the Design section of Ansys like using create face from line etc where you don't put any thickness thus staying in a 2 axis reference system.
Maybe I could do 3 different 2D layers and have Ansys configure the middle layer as a honeycomb through the material selection.
Maybe that could do the trick.
Thank you Michael

[peteroznewman]

Have you successfully solved a 2D plane strain model yet?  Do that for a simple cantilever beam, which is one rectangular surface in 2D. Once you have done that, stack three rectangles to make a sandwich construction cantilever beam and show that result. Do that with isotropic materials. Finally, see if you can assign an orthotropic materials to the center 2D body. I don't know if you can or not. You will have to read the ANSYS help or just try it and see.

Did you read my post on using orthoropic materials to simulate honeycomb core?

[MichaelDelle]

Thank you for your reply again Peter.
I will read your post regarding using orthotropic materials, thank you for mentioning it.
I still have not been able to try what I can do in 2D modelling but I was thinking of doing something like that with the cantilever beams.
Could you explain to me what a 2D plane strain model is ? Material science and FEA analysis is quite new to me so I am constantly learning new things.
Thank you again for your help.
Michael

[peteroznewman]

Here is a good article on 2D Plane Stress and Plane Strain.

[MichaelDelle]

Thank you peter for the article, it is indeed very helpful. 

For my 3D model I am encountering this issue regarding trying a 3 point bending testing. The design modeler wont let me choose simply supported at both ends of my sandwich panel since I am trying to simulate the standard: C365/C365M − 16. Is there a different way I could do that ? 

Thank you.

[peteroznewman]

I can see the face sheets are solid bodies.  What is the honeycomb core, is that also a solid body?  If so, you don't want that, especially if your license has node limits as the free Student license does.

You want to midsurface the solid bodies and use shared topology to connect the edges of the honeycomb to the face sheet surface body. If you can't do that, you can use Bonded Contact, formulation MPC. These will then be meshed with shell elements. 

In either the solid or the shell mesh, you pick the faces or edges on the end of the beam and create a Remote Displacement: Behavior = Rigid

[MichaelDelle]

Dear Peter Thank you so much for your time and help. I will be trying out your advice and see what different results I get.
Just one more thing, the midsurface option, would you suggest I first draw the 2 faces of the sandwich panel and then using the honeycomb Creator make the core ?
Thank you so much for your time.

[peteroznewman]

I have never used the honeycomb creator so I don't know what it delivers, is that sheet bodies or solid model?

[MichaelDelle]

Hello Peter The app states that: Easily create honeycomb core models from a few simple cell properties and bulk size specifications.
When I go to Model it recognises it as a Part > Surface body.
I get a solid body only if I make the honeycomb in Solidworks and then import that design into Ansys Mechanical.

[peteroznewman]

Use the sheet bodies.

[MichaelDelle]

Could you please check the new post that I made since I had this one set as solved ?

Thank you

https://forum.ansys.com/forums/topic/how-to-ensure-to-total-connection-in-a-honeycomb-sandwich-panel/