symplectic.C

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#include "symplectic.H"
#include "addToRunTimeSelectionTable.H"

// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //

namespace Foam
{
namespace RBD
{
namespace rigidBodySolvers
{
    defineTypeNameAndDebug(symplectic, 0);
    addToRunTimeSelectionTable(rigidBodySolver, symplectic, dictionary);
}
}
}


// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //

Foam::RBD::rigidBodySolvers::symplectic::symplectic
(
    rigidBodyMotion& body,
    const dictionary& dict
)
:
    rigidBodySolver(body)
{}


// * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //

Foam::RBD::rigidBodySolvers::symplectic::~symplectic()
{}


// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //

void Foam::RBD::rigidBodySolvers::symplectic::solve
(
    const scalarField& tau,
    const Field<spatialVector>& fx
)
{
    // First simplectic step:
    //     Half-step for linear and angular velocities
    //     Update position and orientation
    qDot() = qDot0() + 0.5*deltaT0()*qDdot();
    q() = q0() + deltaT()*qDot();

    correctQuaternionJoints();

    // Update the body-state prior to the evaluation of the restraints
    model_.forwardDynamicsCorrection(state());

    // Accumulate the restraint forces
    scalarField rtau(tau);
    Field<spatialVector> rfx(fx);
    model_.applyRestraints(rtau, rfx);

    // Calculate the body acceleration for the given state
    // and restraint forces
    model_.forwardDynamics(state(), rtau, rfx);

    // Second simplectic step:
    //     Complete update of linear and angular velocities
    qDot() += 0.5*deltaT()*qDdot();
}


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