Hi, I’m setting a displacement component (u_x=0.1) on the front surface(x=1) for a unit cubic domain to test boundary conditions V = fem.FunctionSpace(domain, element_mix) V_disp = V.sub(0) V_disp_x = V_disp.sub(0) def front(x): return np.isclose(x[0], 1, atol=1.0e-12) and the u_x on front s…

There’s not enough context for anyone to be able to help: the code is just a small snippet the image does not have the coordinate axis, how are we supposed to know which side of the square is aligned with x, y and z? the image does not have a color bar, hence we are left to imagine by our own what…

Here’s the complete code: import numpy as np import matplotlib.pyplot as plt from dolfinx import mesh, fem, io, plot, default_scalar_type from dolfinx.fem.petsc import NonlinearProblem from dolfinx.nls.petsc import NewtonSolver from mpi4py import MPI from petsc4py import PETSc from petsc4py.PETSc …

That’s not the complete code: at the very least the are missing imports. It needs to be something that anyone can copy and paste in order to run on their own.

Hi Francesco, I complement the imports in the above code

The mistake comes from writing out the bc to xdmf file, it should be state = fem.Function(V) fem.petsc.set_bc(state.vector, bcs) with io.XDMFFile(domain.comm, "boundary/test_mixed_bc_topo.xdmf", "w") as xdmf: xdmf.write_mesh(domain) xdmf.write_function(state.sub(0).collapse()) rather than …

3D boundary conditions in mixed formulation

dolfinx

francesco-ballarin August 22, 2024, 5:58am 6

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3D boundary conditions in mixed formulation

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