Learning Forum

[Clement08]

Hello,

I'm trying to simulate a honeycomb structure using shell elements. In order to reduce the computation time and to run a topological optimisation of the core, I have chosen to model the sheets and the core using shell elements. I’m doing a modal analysis of my sandwich panel without adding any boundary condition. When i'm modeling a thin core my results seems to be good (compare to the literature : https://arc.aiaa.org/doi/abs/10.2514/6.2017-5184), However I didn't manage to get good results when I model a thicker core. I have a problem with my contact definition because there are some discontinuities between the sheets and the core in my result.

Sheets are made of aluminium and have a 3mm thickness. The core is a honeycomb material of 30mm, defined by :

I have defined my contacts according to some information available on this forum and on https://www.simutechgroup.com/tips-and-tricks/fea-articles/169-bonded-contact-between-shell-faces-in-ansys-mechanical-workbench-v14-5

I’m supposed to get something close to the next picture (model using 3 layers)

 

For now, i don't understand why my model is not working espacialy because I ran the same simulation with a 0.5mm sheets and a 15mm core and my results were consistent. Plus, I only changed the pinball radius to adapt it to my new model.

Thank you for your help !

[peteroznewman]

I wrote about my honeycomb core sandwich composite in this discussion.

Instead of three sheet bodies, try to make the core out of solid elements and use shell elements only for the skins.

[Clement08]

Thank you for your answer, I already read your topic which is extremely helpful!

I am trying to use 3 sheet bodies because I would like to reduce the computation time. Indeed if you are working with huge parts using solid elements could be a problem.

But what I don’t understand is why my model was working for my first simulation and is not now.