[Libmesh-users] Constrains using penalty

[Вася Б. <gre...@gm...>]

Dear Sirs,

I'm trying to make Libmesh work with a simple linear elasticity problem
using linear systems example 4 as an example. I need to force the top
boundary remain flat, i.e. all normal displacements are of the same value
to be computed.
To obtain this, for example to make the displacements for DOFs i1,i2,i3..in
the same as for the DOF j, I add penalty (1e10) to K(in,in) and subtract it
from K(in,j) meaning to add 1e10*(U_in - U_j) = 0 to the  in'th equation
in the assembly function. But as soon as in and j are on different finite
elements I get the same error no matter which particular c++ function I use
(system.matrix->add(i,j,value)   system.matrix->add_matrix(DenseMatrix)
or system.matrix->add(SparseMatrix) ). I would be very mush obliged if you
helped me.

Kind regards,
Roman Khudobin
Research Assistant ICHPH RAS

[0]PETSC ERROR: --------------------- Error Message
--------------------------------------------------------------
[0]PETSC ERROR: Argument out of range
[0]PETSC ERROR: New nonzero at (17,47) caused a malloc
Use MatSetOption(A, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE) to turn
off this check
[0]PETSC ERROR: See http://www.mcs.anl.gov/petsc/documentation/faq.html for
trouble shooting.
[0]PETSC ERROR: Petsc Release Version 3.6.1, Jul, 22, 2015
[0]PETSC ERROR: ./constrain.o on a arch-linux-c-opt named izmailovo by
gream Tue Oct  6 12:55:21 2015
[0]PETSC ERROR: Configure options --prefix=/opt/petsc/linux-c-opt
--PETSC_ARCH=arch-linux-c-opt --with-shared-libraries=1 --COPTFLAGS=-O3
--CXXOPTFLAGS=-O3 --with-mumps=1 --with-hdf5=1 --with-scalapack=1
--with-suitesparse=1 --with-metis=1 --with-parmetis=1 --with-ptscotch=1
--with-ptscotch-lib="[libesmumps.so,libptscotch.so,libptscotcherr.so,libscotch.so,libscotcherr.so,libbz2.so]"
--with-ptscotch-include=/usr/include/scotch --with-superlu=1
--with-superlu-lib=-lsuperlu --with-superlu-include=/usr/include/superlu
--with-ml=1
[0]PETSC ERROR: #1 MatSetValues_SeqAIJ() line 485 in
/tmp/yaourt-tmp-gream/aur-petsc/src/petsc-3.6.1/src/mat/impls/aij/seq/aij.c
[0]PETSC ERROR: #2 MatSetValues() line 1173 in
/tmp/yaourt-tmp-gream/aur-petsc/src/petsc-3.6.1/src/mat/interface/matrix.c
--------------------------------------------------------------------------
MPI_ABORT was invoked on rank 0 in communicator MPI_COMM_WORLD
with errorcode 1.

NOTE: invoking MPI_ABORT causes Open MPI to kill all MPI processes.
You may or may not see output from other processes, depending on
exactly when Open MPI kills them.
--------------------------------------------------------------------------