Shell model in linear elasticity
Shell model in linear elasticity
Hello,
I would like to use Elmer to calculate deflection of pressure vessel and I wonder if I can use shell model with 2d elements.
Should I use elastic plate solver to do that or linear elasticity is better choise?
In elastic plate solver I am able to define thickness but my model is not flat and I get error
ERROR:: ElementMetric: Degenerate 2D element:
If I use linear elasticity solver instead I din't found way to define thickness, so I was forced to use 3D model with large number of elements, so calculation takes ages.
What is the best way of performing this kind of calculation in Elmer?
Do I have to define symmetry boundary condition in this model by locking displacement in normal direction to symmetry plane or I can use model of whole pressure tank?
Thank You for your help.
Jacek
I would like to use Elmer to calculate deflection of pressure vessel and I wonder if I can use shell model with 2d elements.
Should I use elastic plate solver to do that or linear elasticity is better choise?
In elastic plate solver I am able to define thickness but my model is not flat and I get error
ERROR:: ElementMetric: Degenerate 2D element:
If I use linear elasticity solver instead I din't found way to define thickness, so I was forced to use 3D model with large number of elements, so calculation takes ages.
What is the best way of performing this kind of calculation in Elmer?
Do I have to define symmetry boundary condition in this model by locking displacement in normal direction to symmetry plane or I can use model of whole pressure tank?
Thank You for your help.
Jacek

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Re: Shell model in linear elasticity
Hi Jacek
There is an undocumented shell solver that might be the best choice. It has some limitations though. Plate solver must have the mesh in (x,y) plane.
Peter
There is an undocumented shell solver that might be the best choice. It has some limitations though. Plate solver must have the mesh in (x,y) plane.
Peter
Re: Shell model in linear elasticity
Hi Peter,
Thank You for your response, it is very good news.
I would like to ask you how can I define this solver in Solver Input File and how can set boundary condition of pressure and symmetry for this solver?
Best regards,
Jacek
Thank You for your response, it is very good news.
I would like to ask you how can I define this solver in Solver Input File and how can set boundary condition of pressure and symmetry for this solver?
Best regards,
Jacek
Re: Shell model in linear elasticity
Hi Jacek,
1. The solver can be defined in the Solver Input File as
where,
Filename.f90 is the name of the file containing solver subroutine (residing nearby to the sif, mesh files within the same directory for convenience). Also, AnyNameSolver is the subroutine's name within Filename.f90
i.e.
2. Before, executing via the ElmerSolver, the compilation of the solver has to be done by the elmerf90 command.
This will produce Filename.so output (shared object) file from the Filename.f90 solver subroutine.
The following threads can be relevant for starting with:
viewtopic.php?f=3&t=3759&sid=d490ca6dec ... 4d9b439ca8
viewtopic.php?f=3&t=3754&sid=d490ca6dec ... 4d9b439ca8
Yours
Anil Kunwar
1. The solver can be defined in the Solver Input File as
Code: Select all
Solver 1
...
Procedure = "Filename" "AnyNameSolver"
...
End
Filename.f90 is the name of the file containing solver subroutine (residing nearby to the sif, mesh files within the same directory for convenience). Also, AnyNameSolver is the subroutine's name within Filename.f90
i.e.
Code: Select all
SUBROUTINE AnyNameSolver( Model,Solver,dt,TransientSimulation )
...
Code
...
END SUBROUTINE AnyNameSolver
Code: Select all
$elmerf90 o Filename.so Filename.f90
The following threads can be relevant for starting with:
viewtopic.php?f=3&t=3759&sid=d490ca6dec ... 4d9b439ca8
viewtopic.php?f=3&t=3754&sid=d490ca6dec ... 4d9b439ca8
Yours
Anil Kunwar
Last edited by annier on 31 Dec 2014, 16:08, edited 5 times in total.
Anil Kunwar
Department of Materials Engineering, KU Leuven, Belgium
Department of Materials Engineering, KU Leuven, Belgium
Re: Shell model in linear elasticity
Hi Anil,
Thank you for your help. I have successfully started solver using way you have written, but I found already compiled shellsolve.so file in /elmer/share/elmersolver/lib/ directory, so I just defined solver in solver input file.
But unfortunetly I had to define wrongly boundary condition and maybe compile solver as you told me because I still have same error:
ERROR:: ElementMetric: Degenerate 2D element: 0.0000000000000000
which suggested that this solver see as well only xy plane. Could you tell me where can I find source code of shell solver in order to compile it?
Here is my sif to check what I did wrong:
Thank you for your help again.
Best regards,
Jacek
Thank you for your help. I have successfully started solver using way you have written, but I found already compiled shellsolve.so file in /elmer/share/elmersolver/lib/ directory, so I just defined solver in solver input file.
But unfortunetly I had to define wrongly boundary condition and maybe compile solver as you told me because I still have same error:
ERROR:: ElementMetric: Degenerate 2D element: 0.0000000000000000
which suggested that this solver see as well only xy plane. Could you tell me where can I find source code of shell solver in order to compile it?
Here is my sif to check what I did wrong:
Code: Select all
Header
CHECK KEYWORDS Warn
Mesh DB "." "."
Include Path ""
Results Directory ""
End
Simulation
Max Output Level = 4
Coordinate System = Cartesian 3D
Coordinate Mapping(3) = 1 2 3
Simulation Type = Steady state
Steady State Max Iterations = 1
Output Intervals = 1
Timestepping Method = BDF
BDF Order = 1
Solver Input File = case.sif
Post File = case.ep
End
Constants
Gravity(4) = 0 1 0 9.82
Stefan Boltzmann = 5.67e08
Permittivity of Vacuum = 8.8542e12
Boltzmann Constant = 1.3807e23
Unit Charge = 1.602e19
End
Body 1
Target Bodies(1) = 1
Name = "Body 1"
Equation = 1
Material = 1
Body Force = 1
End
Solver 2
Equation = Linear elasticity
Procedure = "ShellSolve" "ShellSolver"
Exec Solver = Always
Stabilize = True
Bubbles = False
Lumped Mass Matrix = False
Optimize Bandwidth = True
Steady State Convergence Tolerance = 1.0e5
Nonlinear System Convergence Tolerance = 1.0e8
Nonlinear System Max Iterations = 20
Nonlinear System Newton After Iterations = 3
Nonlinear System Newton After Tolerance = 1.0e3
Nonlinear System Relaxation Factor = 1
Linear System Solver = Direct
Linear System Direct Method = MUMPS
End
Solver 1
Equation = Result Output
Output Format = Vtu
Procedure = "ResultOutputSolve" "ResultOutputSolver"
Exec Solver = After All
Output File Name = case
Binary Output = True
Single Precision = True
End
Equation 1
Name = "Equation 1"
Active Solvers(2) = 2 1
End
Material 1
Name = "Steel (stainless  generic)"
Porosity Model = van Genuchten
Thickness = 0.004
Poisson ratio = 0.285
Heat expansion Coefficient = 14.9e6
Electric Conductivity = 1.824e6
Youngs modulus = 200.0e9
Heat Conductivity = 24.0
Sound speed = 5100.0
Heat Capacity = 460.0
Mesh Poisson ratio = 0.285
Density = 7925.0
Poisson ratio = 0.285
Youngs modulus = 200.0e9
End
Body Force 1
Name = "BodyForce 1"
Stress Pressure = 3.0e5
End
Boundary Condition 1
Target Boundaries(1) = 6
Name = "symmetry"
NormalTangential Displacement = True
Displacement 1 = 0
End
Best regards,
Jacek

 Site Admin
 Posts: 3746
 Joined: 22 Aug 2009, 11:57
 Antispam: Yes
 Location: Espoo, Finland
 Contact:
Re: Shell model in linear elasticity
Hi Jacek
There seems to be two consistency tests "shell" and "shell2" among the source code under $ELMERSRC/fem/tests.
The solver itself should be in $ELMERSRC/fem/src/modules/ShellSolver.src
Peter
There seems to be two consistency tests "shell" and "shell2" among the source code under $ELMERSRC/fem/tests.
The solver itself should be in $ELMERSRC/fem/src/modules/ShellSolver.src
Peter
Re: Shell model in linear elasticity
Hi Peter,
Thank You for your help.
I am going to try using this solver and I will report my results here.
Best regards and Happy New Year,
Jacek
Thank You for your help.
I am going to try using this solver and I will report my results here.
Best regards and Happy New Year,
Jacek
Re: Shell model in linear elasticity
Hi Peter,
I have succesfuly used shell solver after studing SIF from test folder.
Thank you
Jacek
I have succesfuly used shell solver after studing SIF from test folder.
Thank you
Jacek
Re: Shell model in linear elasticity
Hello, I wonder if I could piggy back off of this to ask for help. So, I downloaded the ShellSolver as proscribed in this thread and saved it as Shell Solver.f90. However, I don't think that elmerf90.bat was pointing to the right file because I did not have gfortran installed on the computer. It always errors about "cannot find the path specified"
How must I edit the elmerf90 and elmerf90.bat to accomodate my file placement? I am using Windows PowerShell in administrator mode and asked the powershell to do the following:
.\elmerf90 o ShellSolver.dll ShellSolver.f90
elmerf90.bat:
@ECHO OFF
SET LIBDIR=%ELMER_HOME%/bin
SET INCLUDE=%ELMER_HOME%/share/elmersolver/include
SET FC=C:/Elmer8.2Release/bin/mingww64/x86_646.1.0posixsehrt_vtrev0/mingw64/bin/gfortran.exe
SET cmd=%FC% %* fnorangecheck DCONTIG=,CONTIGUOUS DMINGW32 DWIN32 DHAVE_EXECUTECOMMANDLINE DUSE_ISO_C_BINDINGS DUSE_ARPACK O2 g DNDEBUG shared I"%INCLUDE%" L"%LIBDIR%" shared lelmersolver
echo %cmd%
%cmd%
elmerf90:
#!/bin/sh f
if test "$ELMER_LIB" = ""; then
if test "$ELMER_HOME" = ""; then
LIBDIR=C:/Program Files (x86)/Elmer/share/elmersolver/../../lib/elmersolver
INCLUDE=C:/Program Files (x86)/Elmer/share/elmersolver/include
else
LIBDIR=$ELMER_HOME/lib/elmersolver
INCLUDE=$ELMER_HOME/share/elmersolver/include
fi
else
LIBDIR=$ELMER_LIB
INCLUDE=$ELMER_LIB/../include
fi
if test "$ELMER_Fortran_COMPILER" = ""; then
FC=c:/ElmerBuild/mingw/64/mingw64/bin/gfortran.exe
else
FC=$ELMER_Fortran_COMPILER
fi
cmd="$FC $* fnorangecheck DCONTIG=,CONTIGUOUS DMINGW32 DWIN32 DHAVE_EXECUTECOMMANDLINE DUSE_ISO_C_BINDINGS DUSE_ARPACK O2 g DNDEBUG shared I$INCLUDE L$LIBDIR shared lelmersolver"
printf "%s " $cmd
printf "\n"
$FC $* fnorangecheck DCONTIG=,CONTIGUOUS DMINGW32 DWIN32 DHAVE_EXECUTECOMMANDLINE DUSE_ISO_C_BINDINGS DUSE_ARPACK O2 g DNDEBUG shared I$INCLUDE L$LIBDIR shared lelmersolver
# $FC fnorangecheck $*
#$FC $INCLUDE $*
#$FC $INCLUDE $* L$LIBDIR lelmersolver
Thank you!!
How must I edit the elmerf90 and elmerf90.bat to accomodate my file placement? I am using Windows PowerShell in administrator mode and asked the powershell to do the following:
.\elmerf90 o ShellSolver.dll ShellSolver.f90
elmerf90.bat:
@ECHO OFF
SET LIBDIR=%ELMER_HOME%/bin
SET INCLUDE=%ELMER_HOME%/share/elmersolver/include
SET FC=C:/Elmer8.2Release/bin/mingww64/x86_646.1.0posixsehrt_vtrev0/mingw64/bin/gfortran.exe
SET cmd=%FC% %* fnorangecheck DCONTIG=,CONTIGUOUS DMINGW32 DWIN32 DHAVE_EXECUTECOMMANDLINE DUSE_ISO_C_BINDINGS DUSE_ARPACK O2 g DNDEBUG shared I"%INCLUDE%" L"%LIBDIR%" shared lelmersolver
echo %cmd%
%cmd%
elmerf90:
#!/bin/sh f
if test "$ELMER_LIB" = ""; then
if test "$ELMER_HOME" = ""; then
LIBDIR=C:/Program Files (x86)/Elmer/share/elmersolver/../../lib/elmersolver
INCLUDE=C:/Program Files (x86)/Elmer/share/elmersolver/include
else
LIBDIR=$ELMER_HOME/lib/elmersolver
INCLUDE=$ELMER_HOME/share/elmersolver/include
fi
else
LIBDIR=$ELMER_LIB
INCLUDE=$ELMER_LIB/../include
fi
if test "$ELMER_Fortran_COMPILER" = ""; then
FC=c:/ElmerBuild/mingw/64/mingw64/bin/gfortran.exe
else
FC=$ELMER_Fortran_COMPILER
fi
cmd="$FC $* fnorangecheck DCONTIG=,CONTIGUOUS DMINGW32 DWIN32 DHAVE_EXECUTECOMMANDLINE DUSE_ISO_C_BINDINGS DUSE_ARPACK O2 g DNDEBUG shared I$INCLUDE L$LIBDIR shared lelmersolver"
printf "%s " $cmd
printf "\n"
$FC $* fnorangecheck DCONTIG=,CONTIGUOUS DMINGW32 DWIN32 DHAVE_EXECUTECOMMANDLINE DUSE_ISO_C_BINDINGS DUSE_ARPACK O2 g DNDEBUG shared I$INCLUDE L$LIBDIR shared lelmersolver
# $FC fnorangecheck $*
#$FC $INCLUDE $*
#$FC $INCLUDE $* L$LIBDIR lelmersolver
Thank you!!
 Attachments

 ShellSolver.f90
 (179.6 KiB) Downloaded 161 times
Re: Shell model in linear elasticity
Hi,
you don't need to specify the output file name under Windoze.
should be enough.
HTH,
Matthias
you don't need to specify the output file name under Windoze.
Code: Select all
elmerf90 ShellSolver.f90
HTH,
Matthias