Hello, On Thu, May 23, 2019 at 3:45 PM Nikrouz <nikrouz....@gmail.com> wrote:
> Dear All libMesh uses, > > I want to apply traction boundary condition on two of the surfaces of my > geometry. As far as I know, There are two methods > > for defining such a boundary condition: *Using penalty method* The penalty method is used for enforcing Dirichlet boundary conditions. > and > *side_time_derivative method*. This is correct, but it is used within the FEMSystem framework. You'd want to refer to the fem_system examples in this case. > I have a couple of questions: > > > 1- Which method is more straightforward for defining boundary > condition(traction) in libMesh? > Please have a look at the following example: https://github.com/libMesh/libmesh/blob/master/examples/systems_of_equations/systems_of_equations_ex6/systems_of_equations_ex6.C It is a "plain" (non FEMSystem) example. If you look in the assemble() function, you will see that following the element interior loop, there is a loop over boundary elements and then the traction is applied appropriately. HTH, Paul > 2- I have searched different examples in libMesh and I could not find > any case that has used side_time_derivative method(for example defined > in fem-ex3). Is there any example illustrates how can I call the > mentioned method in the code? Where should I call it?How? > > In the example fem3 example, the method need two inputs: > > *bool ElasticitySystem::side_time_derivative (bool request_jacobian,** > ** DiffContext & context)* > > *FEMContext & c = cast_ref<FEMContext &>(context); > > // If we're on the correct side, apply the traction > if (c.has_side_boundary_id(BOUNDARY_ID_MAX_X)) > { > * > > *......* > > > How and where should I use this method in the code to have a traction > boundary condition? > > Thank you everybody! > > > _______________________________________________ > Libmesh-users mailing list > Libmesh-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/libmesh-users > _______________________________________________ Libmesh-users mailing list Libmesh-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libmesh-users
