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Constraints and Contact explanation needed #29062
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Hello I can understand these two for a contact problem
but that one seems excessive
some elements have their centroid inside another element. Are you sure the mesh is well formed? |
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The problem comes when I try to combine the two meshes. I only want to use the Dura surface mesh as a boundary to restrict the movement of the 3D mesh. Unfortunately the surfaces of the pial (surface of the 3D Mesh) and the dura (Surface only mesh) will sometimes overlap. I've tried to combine the 2 in GMSH but ran into problems. I thought I could combine the two in MOOSE. |
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Maybe shrink or move one using the TransformGenerator before combining? MOOSE will let you combine any two mesh with zero checks but that does not mean it can perform a simulation with overlapping meshes |
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There is an embedded constraint for rebar in concrete. That might work for tying the brain to the skull. It requires the rebar to be embedded completely in the concrete in order to apply the nodal constraint. |
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I've been able to dilate the dura mesh in GMSH so that it no longer has any overlap. I'm getting the same error as before. I'm sure I don't have this setup right. I've changed the tag numbers for edge, surface, and volume to be unique. I've also changed the Young's modulus to be more realistic, but I don't think that would matter. Do I need the dura boundary to be fixed? Do the dura and cran boundaries actually need any physics or material properties on them? Sorry for all of the questions, my background is in low frequency EM and my meshes don't usually move. I've posted the input file and results below: input:
Results:
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set a solve_type of PJFNK for now maybe. I dont know whether Contact has 100% implemented Jacobian contributions
no, contact boundaries can move
They need the properties to solve the solid mechanics equations i think. I dont know if it makes sense to solve a contact problem on the surface without solving the solid mechanics equations in the volume |
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Howdy,
I'm attempting to model the displacement due to gravity of a linear elastic material attached on top of non-moving "stem" encased in a shell that is a frictionless surface. I'm reading in a 3D tetrahedral mesh for the linear elastic material and and another mesh for the surrounding shell that is triangles. Both files were made using GMSH and I'm reading in MSH files. The shell is only there as a constraint and will not displace or deform. There is one section of the shell that is "open" to allow for outward movement in that area, but that is a later problem. There's also no need for thermal properties currently.
I'm read over the constraints source documentation as well as the Contact module and I'm having trouble understanding how to implement my problem. I was hoping someone could point me in the right direction. My input file and error results are below:
I apologize for my lack of understanding.
Cheers,
MSH
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