/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | foam-extend: Open Source CFD
   \\    /   O peration     | Version:     3.2
    \\  /    A nd           | Web:         http://www.foam-extend.org
     \\/     M anipulation  | For copyright notice see file Copyright
-------------------------------------------------------------------------------
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/>.

Application
    elasticNonLinTLSolidFoam

Description
    Finite volume structural solver employing a total strain total
    Lagrangian approach.

    Valid for finite strains, finite displacements and finite rotations.

Author
    Micheal Leonard
    Philip Cardiff

\*---------------------------------------------------------------------------*/

#include "fvCFD.H"
#include "constitutiveModel.H"
#include "solidInterface.H"

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

int main(int argc, char *argv[])
{
#   include "setRootCase.H"
#   include "createTime.H"
#   include "createMesh.H"
#   include "createFields.H"
#   include "createSolidInterfaceNonLin.H"

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

    Info<< "\nStarting time loop\n" << endl;

    while(runTime.loop())
    {
        Info<< "Time = " << runTime.timeName() << nl << endl;

#       include "readSolidMechanicsControls.H"

        int iCorr = 0;
        scalar initialResidual = 0;
        lduMatrix::solverPerformance solverPerf;
        scalar relativeResidual = 1.0;
        lduMatrix::debug = 0;

        do
        {
            U.storePrevIter();

            surfaceTensorField shearGradU
            (
                "shearGradU",
                (I - sqr(n)) & fvc::interpolate(gradU)
            );

            fvVectorMatrix UEqn
            (
                fvm::d2dt2(rho, U)
             ==
                fvm::laplacian(2*muf + lambdaf, U, "laplacian(DU,U)")
//            + fvc::div
//              (
//                -(mu + lambda)*gradU
//                + mu*gradU.T()
//                + mu*(gradU & gradU.T())
//                + lambda*tr(gradU)*I
//                + 0.5*lambda*tr(gradU & gradU.T())*I
//                + (sigma & gradU),
//                  "div(sigma)"
//              )
              + fvc::div
                (
                    mesh.magSf()*
                    (
                      - (muf + lambdaf)*(fvc::snGrad(U) & (I - n*n))
                      + lambdaf*tr(shearGradU & (I - n*n))*n
                      + muf*(shearGradU & n)
                      + muf*(n & fvc::interpolate(gradU & gradU.T()))
                      + 0.5*lambdaf*(n*tr(fvc::interpolate(gradU & gradU.T())))
                      + (n & fvc::interpolate(sigma & gradU))
                    )
                )
            );

            if (solidInterfaceCorr)
            {
                solidInterfacePtr->correct(UEqn);
            }

            solverPerf = UEqn.solve();

            if (iCorr == 0)
            {
                initialResidual = solverPerf.initialResidual();
            }

            U.relax();

            //gradU = solidInterfacePtr->grad(U);
            gradU = fvc::grad(U);

#           include "calculateEpsilonSigma.H"
#           include "calculateRelativeResidual.H"

            Info<< "\tTime " << runTime.value()
                << ", Corrector " << iCorr
                << ", Solving for " << U.name()
                << " using " << solverPerf.solverName()
                << ", residual = " << solverPerf.initialResidual()
                << ", relative residual = " << relativeResidual
                << ", inner iterations " << solverPerf.nIterations() << endl;
        }
        while
        (
            solverPerf.initialResidual() > convergenceTolerance
            //relativeResidual > convergenceTolerance
         && ++iCorr < nCorr
        );

        Info<< nl << "Time " << runTime.value() << ", Solving for " << U.name()
            << ", Initial residual = " << initialResidual
            << ", Final residual = " << solverPerf.initialResidual()
            << ", Relative residual = " << relativeResidual
            << ", No outer iterations " << iCorr
            << nl << "ExecutionTime = " << runTime.elapsedCpuTime() << " s"
            << "  ClockTime = " << runTime.elapsedClockTime() << " s"
            << endl;

#       include "writeFields.H"

        Info<< nl << "ExecutionTime = " << runTime.elapsedCpuTime() << " s"
            << "  ClockTime = " << runTime.elapsedClockTime() << " s"
            << endl;
    }

    Info<< "End\n" << endl;

    return(0);
}


// ************************************************************************* //