Commit 858146ca authored by Henry Weller's avatar Henry Weller
Browse files

rigidBodyDynamics: Generalized the interface to the restraints

Now internal forces and restraints may be applied between bodies within
the articulated structure.
parent 39bfef2b
......@@ -50,8 +50,7 @@ namespace restraints
// * * * * * * * * * * * * * * * * Constructors * * * * * * * * * * * * * * //
Foam::RBD::restraints::linearAxialAngularSpring::
linearAxialAngularSpring
Foam::RBD::restraints::linearAxialAngularSpring::linearAxialAngularSpring
(
const word& name,
const dictionary& dict,
......@@ -66,15 +65,17 @@ linearAxialAngularSpring
// * * * * * * * * * * * * * * * * Destructor * * * * * * * * * * * * * * * //
Foam::RBD::restraints::linearAxialAngularSpring::
~linearAxialAngularSpring()
Foam::RBD::restraints::linearAxialAngularSpring::~linearAxialAngularSpring()
{}
// * * * * * * * * * * * * * * Member Functions * * * * * * * * * * * * * * //
Foam::spatialVector
Foam::RBD::restraints::linearAxialAngularSpring::restrain() const
void Foam::RBD::restraints::linearAxialAngularSpring::restrain
(
scalarField& tau,
Field<spatialVector>& fx
) const
{
vector refDir = rotationTensor(vector(1, 0, 0), axis_) & vector(0, 1, 0);
......@@ -131,7 +132,8 @@ Foam::RBD::restraints::linearAxialAngularSpring::restrain() const
<< endl;
}
return spatialVector(moment, Zero);
// Accumulate the force for the restrained body
fx[bodyIndex_] += spatialVector(moment, Zero);
}
......
......@@ -101,8 +101,13 @@ public:
// Member Functions
//- Return the external force applied to the body by this restraint
virtual spatialVector restrain() const;
//- Accumulate the retraint internal joint forces into the tau field and
// external forces into the fx field
virtual void restrain
(
scalarField& tau,
Field<spatialVector>& fx
) const;
//- Update properties from given dictionary
virtual bool read(const dictionary& dict);
......
......@@ -71,7 +71,11 @@ Foam::RBD::restraints::linearDamper::~linearDamper()
// * * * * * * * * * * * * * * Member Functions * * * * * * * * * * * * * * //
Foam::spatialVector Foam::RBD::restraints::linearDamper::restrain() const
void Foam::RBD::restraints::linearDamper::restrain
(
scalarField& tau,
Field<spatialVector>& fx
) const
{
vector force = -coeff_*model_.v(model_.master(bodyID_)).l();
......@@ -80,7 +84,8 @@ Foam::spatialVector Foam::RBD::restraints::linearDamper::restrain() const
Info<< " force " << force << endl;
}
return spatialVector(Zero, force);
// Accumulate the force for the restrained body
fx[bodyIndex_] += spatialVector(Zero, force);
}
......
......@@ -92,8 +92,13 @@ public:
// Member Functions
//- Return the external force applied to the body by this restraint
virtual spatialVector restrain() const;
//- Accumulate the retraint internal joint forces into the tau field and
// external forces into the fx field
virtual void restrain
(
scalarField& tau,
Field<spatialVector>& fx
) const;
//- Update properties from given dictionary
virtual bool read(const dictionary& dict);
......
......@@ -71,7 +71,11 @@ Foam::RBD::restraints::linearSpring::~linearSpring()
// * * * * * * * * * * * * * * Member Functions * * * * * * * * * * * * * * //
Foam::spatialVector Foam::RBD::restraints::linearSpring::restrain() const
void Foam::RBD::restraints::linearSpring::restrain
(
scalarField& tau,
Field<spatialVector>& fx
) const
{
point attachmentPt = bodyPoint(refAttachmentPt_);
......@@ -101,7 +105,8 @@ Foam::spatialVector Foam::RBD::restraints::linearSpring::restrain() const
<< endl;
}
return spatialVector(moment, force);
// Accumulate the force for the restrained body
fx[bodyIndex_] += spatialVector(moment, force);
}
......
......@@ -105,8 +105,13 @@ public:
// Member Functions
//- Return the external force applied to the body by this restraint
virtual spatialVector restrain() const;
//- Accumulate the retraint internal joint forces into the tau field and
// external forces into the fx field
virtual void restrain
(
scalarField& tau,
Field<spatialVector>& fx
) const;
//- Update properties from given dictionary
virtual bool read(const dictionary& dict);
......
......@@ -49,6 +49,7 @@ Foam::RBD::restraint::restraint
:
name_(name),
bodyID_(model.bodyID(dict.lookup("body"))),
bodyIndex_(model.master(bodyID_)),
coeffs_(dict),
model_(model)
{}
......
......@@ -46,6 +46,7 @@ SourceFiles
#include "autoPtr.H"
#include "spatialVector.H"
#include "point.H"
#include "scalarField.H"
#include "runTimeSelectionTables.H"
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
......@@ -75,6 +76,9 @@ protected:
//- ID of the body the restraint is applied to
label bodyID_;
//- Index of the body the force is applied to
label bodyIndex_;
//- Restraint model specific coefficient dictionary
dictionary coeffs_;
......@@ -153,8 +157,13 @@ public:
return bodyID_;
}
//- Return the external force applied to the body by this restraint
virtual spatialVector restrain() const = 0;
//- Accumulate the retraint internal joint forces into the tau field and
// external forces into the fx field
virtual void restrain
(
scalarField& tau,
Field<spatialVector>& fx
) const = 0;
//- Update properties from given dictionary
virtual bool read(const dictionary& dict);
......
......@@ -50,8 +50,7 @@ namespace restraints
// * * * * * * * * * * * * * * * * Constructors * * * * * * * * * * * * * * //
Foam::RBD::restraints::sphericalAngularDamper::
sphericalAngularDamper
Foam::RBD::restraints::sphericalAngularDamper::sphericalAngularDamper
(
const word& name,
const dictionary& dict,
......@@ -66,15 +65,17 @@ sphericalAngularDamper
// * * * * * * * * * * * * * * * * Destructor * * * * * * * * * * * * * * * //
Foam::RBD::restraints::sphericalAngularDamper::
~sphericalAngularDamper()
Foam::RBD::restraints::sphericalAngularDamper::~sphericalAngularDamper()
{}
// * * * * * * * * * * * * * * Member Functions * * * * * * * * * * * * * * //
Foam::spatialVector
Foam::RBD::restraints::sphericalAngularDamper::restrain() const
void Foam::RBD::restraints::sphericalAngularDamper::restrain
(
scalarField& tau,
Field<spatialVector>& fx
) const
{
vector moment = -coeff_*model_.v(model_.master(bodyID_)).w();
......@@ -83,7 +84,8 @@ Foam::RBD::restraints::sphericalAngularDamper::restrain() const
Info<< " moment " << moment << endl;
}
return spatialVector(moment, Zero);
// Accumulate the force for the restrained body
fx[bodyIndex_] += spatialVector(moment, Zero);
}
......
......@@ -93,8 +93,13 @@ public:
// Member Functions
//- Return the external force applied to the body by this restraint
virtual spatialVector restrain() const;
//- Accumulate the retraint internal joint forces into the tau field and
// external forces into the fx field
virtual void restrain
(
scalarField& tau,
Field<spatialVector>& fx
) const;
//- Update properties from given dictionary
virtual bool read(const dictionary& dict);
......
......@@ -29,7 +29,11 @@ License
// * * * * * * * * * * * * * * Member Functions * * * * * * * * * * * * * * //
void Foam::RBD::rigidBodyModel::applyRestraints(Field<spatialVector>& fx) const
void Foam::RBD::rigidBodyModel::applyRestraints
(
scalarField& tau,
Field<spatialVector>& fx
) const
{
if (restraints_.empty())
{
......@@ -41,7 +45,7 @@ void Foam::RBD::rigidBodyModel::applyRestraints(Field<spatialVector>& fx) const
DebugInfo << "Restraint " << restraints_[ri].name();
// Accumulate the restraint forces
fx[master(restraints_[ri].bodyID())] += restraints_[ri].restrain();
restraints_[ri].restrain(tau, fx);
}
}
......
......@@ -322,9 +322,9 @@ public:
//- Return the velocity of the given point on the given body
spatialVector v(const label bodyID, const vector& p) const;
//- Apply the restraints and accumulate the external forces
// into the fx field
void applyRestraints(Field<spatialVector>& fx) const;
//- Apply the restraints and accumulate the internal joint forces
// into the tau field and external forces into the fx field
void applyRestraints(scalarField& tau, Field<spatialVector>& fx) const;
//- Calculate the joint acceleration qDdot from the joint state q,
// velocity qDot, internal force tau (in the joint frame) and
......
......@@ -70,11 +70,12 @@ void Foam::RBD::rigidBodySolvers::CrankNicolson::solve
)
{
// Accumulate the restraint forces
scalarField rtau(tau);
Field<spatialVector> rfx(fx);
model_.applyRestraints(rfx);
model_.applyRestraints(rtau, rfx);
// Calculate the accelerations for the given state and forces
model_.forwardDynamics(state(), tau, rfx);
model_.forwardDynamics(state(), rtau, rfx);
// Correct velocity
qDot() = qDot0() + deltaT()*(aoc_*qDdot() + (1 - aoc_)*qDdot0());
......
......@@ -77,11 +77,12 @@ void Foam::RBD::rigidBodySolvers::Newmark::solve
)
{
// Accumulate the restraint forces
scalarField rtau(tau);
Field<spatialVector> rfx(fx);
model_.applyRestraints(rfx);
model_.applyRestraints(rtau, rfx);
// Calculate the accelerations for the given state and forces
model_.forwardDynamics(state(), tau, rfx);
model_.forwardDynamics(state(), rtau, rfx);
// Correct velocity
qDot() = qDot0()
......
......@@ -79,12 +79,13 @@ void Foam::RBD::rigidBodySolvers::symplectic::solve
model_.forwardDynamicsCorrection(state());
// Accumulate the restraint forces
scalarField rtau(tau);
Field<spatialVector> rfx(fx);
model_.applyRestraints(rfx);
model_.applyRestraints(rtau, rfx);
// Calculate the body acceleration for the given state
// and restraint forces
model_.forwardDynamics(state(), tau, rfx);
model_.forwardDynamics(state(), rtau, rfx);
// Second simplectic step:
// Complete update of linear and angular velocities
......
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