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foam-extend4.1-coherent-io/tutorials/solidMechanics/elasticThermalSolidFoam/hotCylinder/analyticalHotCylinder/analyticalHotCylinder.C
2013-12-11 16:09:41 +00:00

317 lines
8.4 KiB
C

/*---------------------------------------------------------------------------*\
========= |
\\ / F ield | foam-extend: Open Source CFD
\\ / O peration |
\\ / A nd | For copyright notice see file Copyright
\\/ M anipulation |
-------------------------------------------------------------------------------
License
This file is part of foam-extend.
foam-extend is free software: you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation, either version 3 of the License, or (at your
option) any later version.
foam-extend is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with foam-extend. If not, see <http://www.gnu.org/licenses/>.
Description
Generate analytical solution for a thick-walled cylinder with a
temperature gradient.
Temperature field T and stress field sigma and generated.
Based on solution outlined in Timoshenko, Theory of Elasticity.
Author
philip.cardiff@ucd.ie
\*---------------------------------------------------------------------------*/
#include "fvCFD.H"
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
int main(int argc, char *argv[])
{
# include "setRootCase.H"
# include "createTime.H"
# include "createMesh.H"
runTime++;
Info<< "Writing analytical solution for a plain strain cylinder "
<< "with concentric hole,\nwhere"
<< "\n\tinner radius = 0.5"
<< "\n\touter radius = 0.7"
<< "\n\tinner temperature = 100"
<< "\n\touter temperature = 0"
<< "\n\tinner pressure = 0"
<< "\n\touter pressure = 0"
<< "\n\tE = 200e9"
<< "\n\tu = 0.3"
<< "\n\talpha = 1e-5"
<< nl << endl;
//- inner and outer radii and temperatures
scalar a = 0.5;
scalar b = 0.7;
scalar Ti = 100;
scalar To = 0;
//- mechanical and thermal properties
scalar E = 200e9;
scalar nu = 0.3;
scalar alpha = 1e-5;
const volVectorField& C = mesh.C();
//- radial coordinate
volScalarField radii
(
sqrt
(
sqr(C.component(vector::X))
+ sqr(C.component(vector::Y))
)/dimensionedScalar("one", dimLength, 1)
);
const scalarField& rIn = radii.internalField();
Info << "Writing analytical termpature field" << endl;
//- create T field
volScalarField T
(
IOobject
(
"analyticalT",
runTime.timeName(),
mesh,
IOobject::NO_READ,
IOobject::AUTO_WRITE
),
((Ti - To)/Foam::log(b/a))*Foam::log(b/radii)
);
T.write();
//- create sigma field
Info << "\nWriting analytical sigmaR field" << endl;
volScalarField sigmaR
(
IOobject
(
"sigmaR",
runTime.timeName(),
mesh,
IOobject::NO_READ,
IOobject::AUTO_WRITE
),
((alpha*E*(Ti - To))/(2*(1 - nu)*Foam::log(b/a)))*
(
-Foam::log(b/radii)
- (sqr(a)/(sqr(b) - sqr(a)))*(1 - sqr(b)/sqr(radii))*Foam::log(b/a)
)
);
sigmaR.write();
Info << "\nWriting analytical sigmaTheta field" << endl;
volScalarField sigmaTheta
(
IOobject
(
"sigmaTheta",
runTime.timeName(),
mesh,
IOobject::NO_READ,
IOobject::AUTO_WRITE
),
((alpha*E*(Ti - To))/(2*(1 - nu)*Foam::log(b/a)))*
(
1 - Foam::log(b/radii)
- (sqr(a)/(sqr(b) - sqr(a)))*(1 + sqr(b)/sqr(radii))*Foam::log(b/a)
)
);
sigmaTheta.write();
Info << "\nWriting analytical sigmaZ field" << endl;
volScalarField sigmaZ
(
IOobject
(
"sigmaZ",
runTime.timeName(),
mesh,
IOobject::NO_READ,
IOobject::AUTO_WRITE
),
// Timoshenko says this but I am not sure I am not sure the BCs in
// the z direction
// ((alpha*E*(Ti - To))/(2*(1 - nu)*Foam::log(b/a)))*
// (1 - 2*Foam::log(b/radii) - ( 2*sqr(a)/(sqr(b) - sqr(a)))*Foam::log(b/a));
0.3*(sigmaR + sigmaTheta) - E*alpha*(T)
);
sigmaZ.write();
//- create theta field
volScalarField yOverX
(
"yOverX",
Foam::max
(
scalar(-1),
Foam::min
(
scalar(1),
mesh.C().component(vector::Y)/
stabilise
(
mesh.C().component(vector::X),
dimensionedScalar("small", dimLength, SMALL)
)
)
)
);
volScalarField theta
(
IOobject
(
"theta",
runTime.timeName(),
mesh,
IOobject::NO_READ,
IOobject::NO_WRITE
),
Foam::atan(yOverX)
);
//- rotation matrix to convert polar stresses to cartesian
volTensorField rotMat
(
IOobject
(
"rotMat",
runTime.timeName(),
mesh,
IOobject::NO_READ,
IOobject::NO_WRITE
),
mesh,
dimensionedTensor("zero", dimless, tensor::zero)
);
tensorField& rotMatIn = rotMat.internalField();
const scalarField tIn = theta.internalField();
forAll (rotMatIn, celli)
{
const scalar& t = tIn[celli];
rotMatIn[celli] =
tensor
(
Foam::cos(t), Foam::sin(t), 0,
-Foam::sin(t), Foam::cos(t), 0,
0, 0, 1
);
}
forAll (rotMat.boundaryField(), patchi)
{
forAll (rotMat.boundaryField()[patchi], facei)
{
const scalar& t = theta.boundaryField()[patchi][facei];
rotMat.boundaryField()[patchi][facei] =
tensor
(
Foam::cos(t), Foam::sin(t), 0,
-Foam::sin(t), Foam::cos(t), 0,
0, 0, 1
);
}
}
volSymmTensorField sigma
(
IOobject
(
"analyticalSigma",
runTime.timeName(),
mesh,
IOobject::NO_READ,
IOobject::AUTO_WRITE
),
mesh,
dimensionedSymmTensor("zero", dimForce/dimArea, symmTensor::zero)
);
{
symmTensorField& sigmaIn = sigma.internalField();
const scalarField& rIn = sigmaR.internalField();
const scalarField& tIn = sigmaTheta.internalField();
const scalarField& zIn = sigmaZ.internalField();
forAll (sigmaIn, celli)
{
symmTensor sigmaCart
(
rIn[celli], 0, 0,
tIn[celli], 0,
zIn[celli]
);
const tensor& rot = rotMatIn[celli];
sigmaIn[celli] = symm(rot.T() & sigmaCart & rot);
// for general 2-D plain strain problems, the axial stress is:
// (which is not equal to the solution by Timoshenko... hmmmnn)
// sigmaIn[celli][symmTensor::ZZ] =
// 0.3*(sigmaIn[celli][symmTensor::XX]
// + sigmaIn[celli][symmTensor::YY])
// - E*alpha*(T.internalField()[celli]);
}
}
forAll (sigma.boundaryField(), patchi)
{
symmTensorField& pSigma = sigma.boundaryField()[patchi];
const scalarField& pR = sigmaR.boundaryField()[patchi];
const scalarField& pT = sigmaTheta.boundaryField()[patchi];
const scalarField& pZ = sigmaZ.boundaryField()[patchi];
const tensorField pRot = rotMat.boundaryField()[patchi];
forAll (pSigma, facei)
{
const tensor& rot = pRot[facei];
symmTensor sigmaCart
(
pR[facei], 0, 0,
pT[facei], 0,
pZ[facei]
);
pSigma[facei] = symm(rot.T() & sigmaCart & rot);
}
}
Info << "\nWriting analytical sigma tensor" << endl;
sigma.write();
Info << nl << "End" << endl;
return 0;
}
// ************************************************************************* //