Hello to all
Later i was written
>
>
> Message: 2
> Date: Tue, 22 Jan 2008 12:39:34 +0600
> From: "Egor Vtorushin" <[EMAIL PROTECTED]>
> Subject: [Getfem-users] establishing only Neumann and Dirichlet
> conditions for right side vector(volume forces == 0) in case
> of xfem
> dof addition
> To: [email protected]
> Message-ID:
> <[EMAIL PROTECTED]>
> Content-Type: text/plain; charset="koi8-r"
>
> Hello, Yves <[EMAIL PROTECTED]> and all
>
> I've been investigating the crack.cc test and trying to set only Neumann
> and
> Dirichlet conditions for right side vector. So instead of
>
> <code>
> // Defining the volumic source term.
> plain_vector F(nb_dof_rhs * N);
> for (size_type i = 0; i < nb_dof_rhs; ++i)
> gmm::copy(sol_f(mf_rhs.point_of_dof(i)),
> gmm::sub_vector(F, gmm::sub_interval(i*N, N)));
>
> // Volumic source term brick.
> getfem::mdbrick_source_term<> VOL_F(*pINCOMP, mf_rhs, F);
> </code>
>
> i write
> <code>
> // Defining the volumic source term.
> plain_vector F(nb_dof_rhs * N);
> // Volumic source term brick.
> getfem::mdbrick_source_term<> VOL_F(*pINCOMP, mf_rhs, F);
> </code>
>
> Thus now the volume forces is set to zero.
> Now it is necessary to define track forces on boundary where Neumann
> condition type is situated. To do this insted of
> <code>
> // Defining the Neumann condition right hand side.
> gmm::clear(F);
>
> // Neumann condition brick.
>
> getfem::mdbrick_source_term<> NEUMANN(VOL_F, mf_rhs,
> F,NEUMANN_BOUNDARY_NUM);
> </code>
> i write
> <code>
> // Defining the Neumann condition right hand side.
> for (size_type i = 0; i < nb_dof_rhs; ++i){
>
> F[i] = 0;
> F[i+1]=0.1*rhs_func(mf_rhs.point_of_dof(i)[0],
> mf_rhs.point_of_dof(i)[1]);
> }
> // Neumann condition brick.
>
> getfem::mdbrick_source_term<> NEUMANN(VOL_F, mf_rhs, F,
> NEUMANN_BOUNDARY_NUM);
> </code>
> Here rhs_func the auxiliary function equaled to 1 near(to 1e-8) the
> boundary
> where Nuemann condition type is situated. But results of program does not
> corresponded with BC we just described. So the question - how can i
> establish the BC i need(only Neumann and Dirichlet conditions for right
> side
> vector).
> I think the reason that actually number of dof is greater than vector F
> size because of xfem addition for describing crack and singularity but i
> don't now how to solve this situation. Anybody can help me?
>
> Regards, Egor Vtorushin
It is clear(now for me too) that there was incorrect lines in my defining
right side vector F code
The my wrong code is given
<code>
// Defining the Neumann condition right hand side.
for (size_type i = 0; i < nb_dof_rhs; ++i){
F[i] = 0;
F[i+1]=0.1*rhs_func(mf_rhs.point_of_dof(i)[0],
mf_rhs.point_of_dof(i)[1]);
}
// Neumann condition brick.
getfem::mdbrick_source_term<> NEUMANN(VOL_F, mf_rhs, F,
NEUMANN_BOUNDARY_NUM);
</code>
Since i correct it to
<code>
// Defining the Neumann condition right hand side.
for (size_type i = 0; i < nb_dof_rhs; ++i){
F[i*N] = 0;
F[i*N+1]=0.1*rhs_func(mf_rhs.point_of_dof(i)[0],
mf_rhs.point_of_dof(i)[1]);
}
// Neumann condition brick.
getfem::mdbrick_source_term<> NEUMANN(VOL_F, mf_rhs, F,
NEUMANN_BOUNDARY_NUM);
</code>
the program works fine(besides error in mm::SuperLU_solve, so i add boundary
fragment with Dirichlet conditions to make coercitivity)
Sorry for my carelessness.
Regards, Egor Vtorushin.
_______________________________________________
Getfem-users mailing list
[email protected]
https://mail.gna.org/listinfo/getfem-users
