Learning Forum

[Jorge Carames]

Hello Everyone,

I am trying to model an artificial intervertebral disc.  It is made up of a hyperelastic material core located between two bodies of rigid material, as seen in the image.  

The top layer applies compression directly onto the hyperelastic material. I am unable to perform the simulation; I believe it is due to the contacts between the bodies. What would be the correct configuration? To apply the force on the top layer, I use "Force" and the piece is fixed by the bottom face with "Fixed Support".

Thank you in advance.

[Sampat Kumar]

Hello 
Based on the provided scenario, you can insert a Contact with the rigid body face on the Target side, and apply the softer material side face to the contact side. used substeps instead of auto time stepping default feature. You can use a little bit larger number of substeps to capture the contact behavior properly. 

Best Regards,
Sampat

[Jorge Carames]

Hello.

Thanks for your reply. I have created two frictionless contacts. If I solve the problem supressing the top body and applying the force directly in the hiperelastic, it works properly (image 1). However, if I try to solve applying the force in the top body to compress the rest of the piece, I get an error "An internal solution magnitude limit was exceeded" (image 2). I suppose the problem is in this contact. How can i fix it?

  Image 1

Image 2

[Sampat Kumar]

Hi 
Can you try to apply the "add offset ramped effect" in the connection and see if this helps you or not?
Also, increase the number of substeps to capture the contact properly. 

Best Regards,
Sampat

[Jorge Carames]

 

I still get the same error. Could it be that it’s not enough defined? I mean, I need the top piece compressing in -Z direction and maybe applying the force in this direction is insufficient.