Impact simulation

[kevinarden]

That kind of simulaton requires an eularian approch where the mesh is fixed and the material flows through the mesh depending on the loads and inetria. I have done this in abaqus but have not investigated elmer to see if it has eularian capability. I will take a look.

[Kat]

Do you know if the mesh can separate? Like shrapnel for example?
IIRC This type of analysis requires an element type (or failure criteria) that is able to disconnect elements from there neighbor elements when they reach the failure criteria

[kevinarden]

Only if the code is using the Lagrangian formualtion, Difference between Lagrangian and Eulerian Mesh, is in Lagrangian the mesh has to adapt to the loads, in Eulerian the mesh is fixed and the materials flow through the fixed cells as they deform and splinter. The type of stuff you are looking at requires an eularian formulation. The Lagrangian mesh is attached to the material points. As the material deforms, the mesh deform with it. In contrast, the Eulerian mesh acts as a background grid. The mesh stays the same as the material deforms (or flows) inside the mesh.

Your desired simulaton is best suited to eularian,

[kevinarden]

https://www.youtube.com/watch?v=J9f_fmgMHfY

The mesh is fixed and the material flows through the mesh. This eliminates the problem of the mesh having to separate.

Eularian formulation.

[Kat]

Oh no I am wanting the mesh to separate. So for example a harden metal plate is shot the it can shrapnel off sending off metal chunks and such
So I think the Lagrangian formulation would work better for me.
Unless I don't understand correctly

Like in this video the bullet comes apart
https://www.youtube.com/watch?v=d3GuRXCSZio

[kevinarden]

I do not think that is poosible in lagrangian, only in eularian, the post process software made the nice video without showing the element grid. Elmer may do eularian but I have not researched it yet.

[Kat]

If needed I was just gonna try and code it in myself into the UNIGINE SDK but Eulerian noted. Though I've seen you can mix the two together? Would that maybe be better? I just wanna make sure I can make sure the bullets and armor fragment correctly

[kevinarden]

https://joelcfd.com/projects/bes/

looks interesting

Elmer has some Eulerian capability but I don't think it will fully support your case.