Hi. I am trying to learn to how to define the materials of a 3D model on FENICSx platform, but with a property of spatially varying elastic modulus. I have created the material file .inp by Abaqus (every element of the model has been defined by its own different material paramters), But I don’t know…

Consider the following: import dolfinx.io.gmshio import meshio from mpi4py import MPI def create_mesh(mesh, cell_type, prune_z=False): cells = mesh.get_cells_type(cell_type) points = mesh.points[:,:2] if prune_z else mesh.points out_mesh = meshio.Mesh(points=points, cells={cell_type: …

See for instance: I/O from XDMF/HDF5 files in dolfin-x - #48 by dokken or Dolfinx discontinous expression - #3 by dokken

Thanks a lot, Prof Dokken! Let me learn first.

Hi, Prof Dokken. Sorry to bother you. I have test the code you provided in Dolfinx discontinous expression import dolfinx.io import dolfinx from mpi4py import MPI mesh = dolfinx.mesh.create_unit_square(MPI.COMM_WORLD, 5, 5) V = dolfinx.fem.FunctionSpace(mesh, ("DG", 0)) v = dolfinx.fem.Function(V…

The dofs of a DG-space is aligned with the local cell index. If you get an unexpected result, I would suggest you add a print statement inside your loop to see what the midpoint is. With the snippet you have supplied above, it seems like you have gotten a sensible result?

Thank you for your quick reply. Since the dof is aligned with the cell index, I think I know how to do next.

By the way, I have tried the second method about MeshFunction mentioned in Dolfinx discontinous expression import dolfinx.io import dolfinx from mpi4py import MPI mesh = dolfinx.mesh.create_unit_square(MPI.COMM_WORLD, 5, 5) V = dolfinx.fem.FunctionSpace(mesh, ("DG", 0)) v2 = dolfinx.Function(V) mf…

The post is a bit out of date, as it is from 2020. MeshFunction has been replaced with dolfinx.mesh.meshtags. see for instance my demos for examples: Defining subdomains for different materials — FEniCSx tutorial

Sorry, Prof Dokken. I’ve tried to define the material by the API of tabulate_dof_coordinates and setValueLocal. But the results are mismatched. The coordinate array given by x = V.tabulate_dof_coordinates() is not aligned with the element index defined by the xdmf file of model. How can I resolve t…

Please create a minimal reproducible example, as I cannot say what goes wrong from just looking at a screenshot of the result.

How to define spatially varying materials

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dokken September 5, 2023, 8:07am 13

You can access the original cell index as done here: Wrong order of dofs after creating mesh from lists of points and cells - #5 by dokken

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How to define spatially varying materials

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