Learning Forum

[271356]

Hi, I'm currently working on an explosion simulation in Autodyn and encountering a problem with the shell elements. I’ve assigned boundary conditions and joints, but the shells show no response — the results appear to be null. Additionally, I selected momentum variables in the unstructured solver, but they don't seem to be visible in the output. Could you please advise on what might be causing this issue?
Thank you for your attention.

[Chris Quan]

For shell elements, in order to make Euler/Lagrange coupling work, a coupling thickness is applied to shell elements to thicken them so they could block faces of Euler grid as well as Euler material flow.

The coupling thickness is applied automatically in Explicit Dynamics system and is set to twice of the coupled Euler element size. 

If Autodyn is used, user needs to set the coupling thickness via Interations -> Euler/Lagrange -> Euler-Lagrange/Shell Interactions. The default option is Manual, which requires user to specify the thickness and Direction (Centered, Positive, Negative). Fully Auto (same as it in Explicit Dynamics system) and Semi Auto are also available to use.

[271356]

Thanks for your instructions, but they only work for Lagrange and Euler parts — not for shell. When I try to create a new coupling, I’m unable to select a shell part. Do you know what I should do next?

[Chris Quan]

For Autodyn 2D Euler/Lagrange coupling, you need to use Polygon to define the flow constraints for Eulerian materials.

[271356]

Thanks. Can you tell me how to view the moment (X, Y) and force (X, Y) for a shell? I selected the unstructured variables, but I don't see them in the contour or history output.

[241spicy]

Hi everyone, I'm struggling with shell elements in my Autodyn explosion simulation. Boundary conditions and joints are set, but the shells aren't responding, giving null results. It feels like gliding downhill with no traction, a bit like a Snow Rider losing control! I also can't see the momentum variables I selected in the output. Any tips on what's causing this silent treatment? Thanks in advance for any guidance.

[271356]

Hi,
Do you include Lagrange/Lagrange or Euler/Lagrange interactions? For example, when checking pressure, the shell might not display this information.