>
> As you advised, I edited that part in "RB_construction.C" and ran my code
> again.
>
> As a result, I could obtain the correct result.
>
OK, good to hear! By the way, I didn't mean that you need to edit
rb_construction.C. The impose_internal_fluxes boolean is a public member of
the RBConstruction class, so you can just set impose_internal_fluxes to
true in the RBConstruction object that you're using. You can do that in
your application code, no need to edit the libMesh library code.
Best,
David
> ----- Original Message -----
> From : David Knezevic <david.kneze...@akselos.com>
> To : "Shinseong Kang" <ss.k...@pusan.ac.kr>
> Cc : "Libmesh user group" <libmesh-users@lists.sourceforge.net>
> Sent : 2019-10-08 21:53:36
> Subject : Re: [RB] Assembly for a Interior (neighbor) side between elements
>
>
> Hello,
>
> I think your approach is basically correct, but issue is that by default
> the code skips assembly on internal sides for the sake of efficiency (since
> usually we do not need to do assembly on internal sides). In order to not
> skip internal sides you can set "impose_internal_fluxes = true" on your
> RBConstruction object. That is false by default and if you look
> at RBConstruction::add_scaled_matrix_and_vector() you will see that you
> have to set it to true in order to loop over non-boundary sides.
>
> Let me know if that works for you.
>
> Best,
> David
>
> On Tue, Oct 8, 2019 at 6:57 AM Shinseong Kang <ss.k...@pusan.ac.kr> wrote:
>
>> Hello, all.
>>
>>
>>
>> I tried to define an output in a simply supported 3-D beam problem.
>>
>> My output is an average displacement in the middle of the beam.
>>
>> For simplicity, I only used two brick elements, i.e, ■|■, where "■" is
>> an element, and "|" is a location I want to compute the average output.
>>
>>
>> To do this, I utilized the codes in RB example 5.
>>
>> First, I declared "ThetaOutput" (parameter-dependent term) and
>> also declared "AssemblyOutput" (parameter-independent term) as follows:
>>
>> =======================================
>>
>> void AssemblyOutput::boundary_assembly(FEMContext & c)
>>
>> {
>>
>> if (rb_sys.get_mesh().get_boundary_info().has_boundary_id
>>
>> (&c.get_elem(), c.side, BOUNDARY_ID_MID))
>>
>> {
>>
>> const unsigned int u_var = 0;
>>
>> const unsigned int v_var = 1;
>>
>>
>> FEBase * side_fe = libmesh_nullptr;
>>
>> c.get_side_fe(v_var, side_fe);
>>
>>
>> const std::vector<Real> & JxW_side = side_fe->get_JxW();
>>
>>
>> const std::vector<std::vector<Real> > & phi_side =
>> side_fe->get_phi();
>>
>>
>> const unsigned int n_v_dofs = c.get_dof_indices(v_var).size();
>>
>>
>> unsigned int n_qpoints = c.get_side_qrule().n_points();
>>
>> DenseSubVector<Number> & output = c.get_elem_residual(v_var);
>>
>>
>> for (unsigned int qp=0; qp < n_qpoints; qp++)
>>
>> for (unsigned int i=0; i < n_v_dofs; i++)
>>
>> output(i) += JxW_side[qp] * (1. * phi_side[i][qp]);
>>
>> }
>>
>> }
>>
>> =======================================
>> As you can see, The above code is very similar to "Assemblyp1" in
>> "assembly.C" of RB example 5.
>>
>> However, I could not obtain the correct output because the above code
>> cannot deal with interior side between elements.
>> In other words, the boundary information of FEMContext only include outer
>> side.
>>
>> I tried to find another way, but I could not find the right solution.
>> Therefore, I'd like your help.
>>
>> To summarize my questions are as follows:
>> 1. Is there any way to assemble an interior (neighbor) side between
>> elements?
>> 2. How to compute an average displacement for the middle of a beam in
>> terms of the RB codes?
>>
>>
>> Thank you.
>>
>>
>>
>> Best regards,
>>
>> Kang
>>
>>
>> ------------------------------------------------------------
>>
>> Shinseong Kang
>> Graduate Student
>> Pusan National University, South Korea
>>
>> Tel.: +82-051-510-3052
>> H.P.: +82-010-9770-6595
>> E-mail: ss.k...@pusan.ac.kr
>>
>> ------------------------------------------------------------
>>
>
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