I have a function space, created from a MixedElement, consisting of a number of scalar function spaces and 1 vector function space. I can apply a Dirichlet boundary condition to the scalar function spaces, but I haven’t been able to do the same for the vector function space. A MWE is: import ufl i…

[image] nav: RuntimeError: Creating a DirichletBC using a Constant is not supported when the Constant size is not equal to the block size of the constrained (sub-)space. Use a Function to create the DirichletBC. As the error message says, the first input has to be a function. In your code yo…

Hi dokken, I have a question: This code seems you fix the boundary by setting the first component of displacements by 1 and the second component free. How to write the codes if I want to impose (1.0,1.0) at the boundary nodes?

See for instance: Implementation — FEniCSx tutorial

Thanks dokken this works when if I use a single-element space. When I have a mixed-function space it doesn’t work: “u_D = np.array([0, 0], dtype=default_scalar_type) bc = fem.dirichletbc(u_D, boundary_dofs_b, ME.sub(1))”

Without a minimal reproducible example, it is quite tedious for me to help you. You should use something along the lines of what is written in [image] How to impose a Dirichlet bc on a vector sub-space? Errors As the error message says, the first input has to be a functio…

How to impose a Dirichlet bc on a vector sub-space?

Errors

yymunrry April 19, 2024, 1:59pm 7

Thanks! I create a new post. Please seehttps://fenicsproject.discourse.group/t/impose-a-dirichlet-bc-on-a-vector-sub-space/14346

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How to impose a Dirichlet bc on a vector sub-space?

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