void Foam::dirichletNeumannFriction::correct
(
const vectorField& slavePressure,
const PrimitivePatch<face, List, pointField>& masterFaceZonePatch,
const PrimitivePatch<face, List, pointField>& slaveFaceZonePatch,
const intersection::algorithm alg,
const intersection::direction dir,
const word interpolationMethod,
const word fieldName,
const Switch orthotropic,
const word nonLinear,
const vectorField& slaveFaceNormals
)
{
const fvMesh& mesh = mesh_;
const label slavePatchIndex = slavePatchID();
const label masterPatchIndex = masterPatchID();
contactIterNum_++;
// we have local masterDU and we want to interpolate it to the slave
// to get local masterDUInterpToSlave (i.e. masterDU interpolated
// to the slave)
// so the method is:
// create global masterDU field
// interpolate global masterDU from master global face zone to
// slave global zone
// then find local masterDUInterpToSlave from the global interpolated field
vectorField masterDUInterpToSlave
(mesh.boundaryMesh()[slavePatchIndex].size(), vector::zero);
// global master DU
vectorField globalMasterDU(masterFaceZonePatch.size(), vector::zero);
// lookup current displacement field
const volVectorField& dispField =
mesh.objectRegistry::lookupObject<volVectorField>(fieldName);
// local master and slave DU increment
vectorField masterDU = dispField.boundaryField()[masterPatchIndex];
vectorField slaveDU = dispField.boundaryField()[slavePatchIndex];
if (fieldName == "U")
{
// lookup old U
const volVectorField& dispOldField =
mesh.objectRegistry::lookupObject<volVectorField>(fieldName+"_0");
// subtract old U
masterDU -= dispOldField.boundaryField()[masterPatchIndex];
slaveDU -= dispOldField.boundaryField()[slavePatchIndex];
}
else if (fieldName != "DU")
{
FatalError << "dirichletNeumannFriction::correct()\n"
" The displacement field must be called U or DU"
<< exit(FatalError);
}
// put local masterDU into globalMasterDU
const label masterPatchStart
= mesh.boundaryMesh()[masterPatchIndex].start();
forAll(masterDU, i)
{
globalMasterDU[
mesh.faceZones()[masterFaceZoneID()
].whichFace(masterPatchStart + i)] =
masterDU[i];
}
//- exchange parallel data
// sum because each face is only on one proc
reduce(globalMasterDU, sumOp<vectorField>());
// globalMasterDU is interpolated to the slave
vectorField globalMasterDUInterpToSlave
(slaveFaceZonePatch.size(), vector::zero);
// interpolate DU from master to slave using inverse distance or ggi
if (interpolationMethod == "patchToPatch")
{
PatchToPatchInterpolation<
PrimitivePatch<
face, List, pointField
>, PrimitivePatch<face, List, pointField>
> masterToSlavePatchToPatchInterpolator
(
masterFaceZonePatch, // from zone
slaveFaceZonePatch, // to zone
alg,
dir
);
globalMasterDUInterpToSlave =
masterToSlavePatchToPatchInterpolator.faceInterpolate<vector>
(
globalMasterDU
);
}
else if (interpolationMethod == "ggi")
{
GGIInterpolation<
PrimitivePatch<
face, List, pointField
>, PrimitivePatch< face, List, pointField >
> masterToSlaveGgiInterpolator
(
masterFaceZonePatch, // master zone
slaveFaceZonePatch, // slave zone
tensorField(0),
tensorField(0),
vectorField(0),
0.0,
0.0,
true,
ggiInterpolation::AABB
);
globalMasterDUInterpToSlave =
masterToSlaveGgiInterpolator.masterToSlave
(
globalMasterDU
);
}
else
{
FatalError << "dirichletNeumannFriction::correct()\n"
"interpolationMethod " << interpolationMethod << " not known\n"
"interpolationMethod must be patchToPatch or ggi"
<< exit(FatalError);
}
// now put global back into local
const label slavePatchStart
= mesh.boundaryMesh()[slavePatchIndex].start();
forAll(masterDUInterpToSlave, i)
{
masterDUInterpToSlave[i] =
globalMasterDUInterpToSlave
[
mesh.faceZones()[slaveFaceZoneID()].whichFace(slavePatchStart + i)
];
}
// Now masterDUInterpToSlave should have masterDU interpolated to the slave
// Calculate current slave shear traction from the normal gradient field
const fvPatch& slavePatch = mesh.boundary()[slavePatchIndex];
const fvPatchField<tensor>& gradField =
slavePatch.lookupPatchField<volTensorField, tensor>
("grad(" + fieldName + ")");
bool incremental(fieldName == "DU");
vectorField slaveShearTraction
(
(I - sqr(slaveFaceNormals))
& tractionBoundaryGradient::traction
(
gradField,
fieldName,
"U",
slavePatch,
orthotropic,
nonLinearGeometry::nonLinearNames_[nonLinear],
incremental
)
);
// algorithm
// if the face pressure is negative/zero then the friction is zero
// so set valueFrac to zero and traction to zero
// if the face pressure is positive and the shear traction is less
// than fricCoeff*pressure then this is a sticking face so
// set the valueFrac to (I-n^2) and set the disp to remove any
// slip
// if the face pressure is positive and the shear traction is greater
// than fricCoeff*pressure then this is a slipping face so
// set the valueFrac to zero and set the shear traction to
// fricCoeff*pressure in the opposite direction to slip
// if the shear traction on a slipping face is acting in the same
// direction as the slip then this face should not be slipping
// so we make it a sticking face
// const volVectorField& prevSlaveDispField =
// mesh.objectRegistry::lookupObject<volVectorField>(fieldName);
const vectorField prevSlaveShearDisp =
(I - sqr(slaveFaceNormals))
& dispField.boundaryField()[slavePatchIndex];
label numSlipFaces = 0;
label numStickFaces = 0;
scalarField& stickSlip = stickSlipFaces();
const scalarField magSlavePressure = mag(slavePressure);
scalar maxMagSlavePressure = 0.0;
if (slavePressure.size() > 0) maxMagSlavePressure = max(magSlavePressure);
reduce(maxMagSlavePressure, maxOp<scalar>());
// slip is the difference between the master tangential DU
// and slave tangential DU
vectorField slip =
(I - sqr(slaveFaceNormals)) &
( slaveDU - masterDUInterpToSlave);
// under-relax the slip
slip = relaxationFactor_*slip + (1.0 - relaxationFactor_)*oldSlip_;
oldSlip_ = slip;
vectorField slipDir = slip/(mag(slip)+SMALL);
const scalar pressureTol = 1e-3*maxMagSlavePressure;
// first we calculate slaveDisp assuming every face is sticking
// and we calculate slaveTraction assuming every face is sliding
// then we use the slaveValueFrac to set the face to slip/stick
// depending on the slip function
slaveDisp_ = -slip + prevSlaveShearDisp;
//slaveDisp_ = -slip + slaveDisp_; // see if convergence is better
scalarField slipTrac = frictionLawPtr_->slipTraction(magSlavePressure);
// new
forAll(slaveDisp_, facei)
{
if (mag(slavePressure[facei]) < pressureTol)
{
// not in contact
slaveDisp_[facei] = prevSlaveShearDisp[facei];
slaveTraction_[facei] = vector::zero;
slaveValueFrac_[facei] = symmTensor::zero;
stickSlip[facei] = -1;
}
else if (
(mag(slaveShearTraction[facei]) > 0.999*slipTrac[facei])
&&
((slip[facei] & slaveShearTraction[facei]) < 0.0) // opposite directions
)
{
// slip
slaveDisp_[facei] =
-slip[facei] + prevSlaveShearDisp[facei]; // better convergence
slaveTraction_[facei] = -slipDir[facei] * slipTrac[facei];
slaveValueFrac_[facei] = symmTensor::zero;
numSlipFaces++;
stickSlip[facei] = 0;
}
else
{
// stick
slaveDisp_[facei] = -slip[facei] + prevSlaveShearDisp[facei];
slaveTraction_[facei] = -slipDir[facei] * slipTrac[facei];
//slaveTraction_[facei] = slaveShearTraction[facei];
//slaveTraction_[facei] = vector::zero;
slaveValueFrac_[facei] = (I - sqr(slaveFaceNormals[facei]));
numStickFaces++;
stickSlip[facei] = 2;
}
}
// slaveTraction_ = -slipDir * slipTrac;
// // slipFunc is 1.0 for slip and 0.0 for stick
// // scalarField slipFunc = mag(slaveShearTraction) - 0.999*slipTrac;
// scalarField slipFunc = mag(slaveShearTraction) - slipTrac;
// //slipFunc /= mag(slipFunc+SMALL); // bugfix add SMALL
// //slipFunc = max(slipFunc, 0.0);
// //const scalar slipStressTol = 1e-4*gMax(mag(slaveShearTraction));
// const scalar pressureTol = 1e-3*maxMagSlavePressure;
// forAll(slipFunc, facei)
// {
// if (slipFunc[facei] > pressureTol)
// {
// slipFunc[facei] = 1.0;
// }
// else
// {
// slipFunc[facei] = 0.0;
// }
// }
// // if the slip and trac are in the same direction then we will change
// // the face from slip to stick
// // {
// // scalarField changeFace = slip & slaveTraction_;
// // forAll(changeFace, facei)
// // {
// // if (changeFace[facei] > SMALL)
// // {
// // slipFunc[facei] = 0.0;
// // }
// // }
// // }
// // stickSlip
// // -1 for faces not in contact
// // 0 for slipping faces
// // 1 for stick faces
// stickSlip = (1.0 - slipFunc);
// // const scalar pressureTol = 1e-3*maxMagSlavePressure;
// forAll(slip, facei)
// {
// if (magSlavePressure[facei] < pressureTol)
// {
// stickSlip[facei] = -1;
// }
// }
// //slaveValueFrac_ = (1.0 - slipFunc) * (I - sqr(slaveFaceNormals));
// slaveValueFrac_ = max(stickSlip, 0.0) * (I - sqr(slaveFaceNormals));
// // set valueFace to zero for faces not in contact
// // and also reset traction on sticking faces and displacement
// // on slipping faces
// forAll(slip, facei)
// {
// if (magSlavePressure[facei] < pressureTol)
// {
// slaveDisp_[facei] = prevSlaveShearDisp[facei];
// slaveTraction_[facei] = vector::zero;
// slaveValueFrac_[facei] = symmTensor::zero;
// if ( mag(stickSlip[facei] + 1) > SMALL)
// Info << "face " << facei << "changed to tracFree" << endl;
// stickSlip[facei] = -1;
// }
// else if (slipFunc[facei] > SMALL)
// {
// slaveDisp_[facei] = prevSlaveShearDisp[facei];
// numSlipFaces++;
// if ( mag(stickSlip[facei]) > SMALL)
// Info << "face " << facei << "changed to slip" << endl;
// stickSlip[facei] = 0;
// }
// else
// {
// //slaveTraction_[facei] = slaveShearTraction[facei];
// numStickFaces++;
// if ( mag(stickSlip[facei] - 1) > SMALL)
// Info << "face " << facei << "changed to stick" << endl;
// stickSlip[facei] = 1;
// }
// }
// correct oscillations
if (oscillationCorr_)
{
//correctOscillations(slaveFaceZonePatch);
// interpolate face values to points then interpolate back
// this essentially smooths the field
primitivePatchInterpolation localSlaveInterpolator
(mesh.boundaryMesh()[slavePatchIndex]);
vectorField slaveDispPoints
(mesh.boundaryMesh()[slavePatchIndex].nPoints(), vector::zero);
for (int i=0; i<smoothingSteps_; i++)
{
slaveDispPoints =
localSlaveInterpolator.faceToPointInterpolate<vector>(slaveDisp_);
slaveDisp_ =
localSlaveInterpolator.pointToFaceInterpolate<vector>
(slaveDispPoints);
// make sure no normal component
slaveDisp_ = (I - sqr(slaveFaceNormals)) & slaveDisp_;
}
}
// under-relax traction
slaveDisp_ =
relaxationFactor_*slaveDisp_
+ (1.0 - relaxationFactor_)*prevSlaveShearDisp; //oldSlaveDisp_;
oldSlaveDisp_ = slaveDisp_;
slaveValueFrac_ =
relaxationFactor_*slaveValueFrac_
+ (1.0 - relaxationFactor_)*oldSlaveValueFrac_;
oldSlaveValueFrac_ = slaveValueFrac_;
slaveTraction_ =
relaxationFactor_*slaveTraction_
+ (1.0 - relaxationFactor_)*oldSlaveTraction_;
oldSlaveTraction_ = slaveTraction_;
stickSlip =
relaxationFactor_*stickSlip + (1.0 - relaxationFactor_)*oldStickSlip_;
oldStickSlip_ = stickSlip;
// get global values
// in parallel, the log is poluted with warnings that
// I am getting max of a list of size zero so
// I will get the max of procs which have some
// of the slave faces
//scalar maxMagMasterTraction = gMax(mag(slaveTraction_))
scalar maxMagMasterTraction = 0.0;
if (slaveTraction_.size() > 0)
{
maxMagMasterTraction = max(mag(slaveTraction_));
}
reduce(maxMagMasterTraction, maxOp<scalar>());
reduce(numSlipFaces, sumOp<int>());
reduce(numStickFaces, sumOp<int>());
// master writes to contact info file
if (Pstream::master() && (contactIterNum_ % infoFreq_ == 0))
{
OFstream& contactFile = *contactFilePtr_;
int width = 20;
contactFile << mesh.time().value();
contactFile.width(width);
contactFile << contactIterNum_;
contactFile.width(width);
contactFile << relaxationFactor_;
contactFile.width(width);
contactFile << numSlipFaces;
contactFile.width(width);
contactFile << numStickFaces;
contactFile.width(width);
contactFile << maxMagMasterTraction << endl;
}
}
void Foam::dirichletNeumannFriction::correct
(
const vectorField& slavePressure,
const PrimitivePatch<face, List, pointField>& masterFaceZonePatch,
const PrimitivePatch<face, List, pointField>& slaveFaceZonePatch,
const intersection::algorithm alg,
const intersection::direction dir,
const word interpolationMethod,
const word fieldName,
const Switch orthotropic,
const word nonLinear,
const vectorField& slaveFaceNormals
)
{
const fvMesh& mesh = mesh_;
const label slavePatchIndex = slavePatchID();
const label masterPatchIndex = masterPatchID();
contactIterNum_++;
// we have local masterDU and we want to interpolate it to the slave
// to get local masterDUInterpToSlave (i.e. masterDU interpolated to
// the slave)
// so the method is:
// create global masterDU field
// interpolate global masterDU from master global face zone to slave
// global zone
// then find local masterDUInterpToSlave from the global interpolated field
vectorField masterDUInterpToSlave
(mesh.boundaryMesh()[slavePatchIndex].size(), vector::zero);
// global master DU
vectorField globalMasterDU(masterFaceZonePatch.size(), vector::zero);
// lookup current displacement field
const volVectorField& dispField =
mesh.objectRegistry::lookupObject<volVectorField>(fieldName);
// local master and slave DU increment
vectorField masterDU = dispField.boundaryField()[masterPatchIndex];
vectorField slaveDU = dispField.boundaryField()[slavePatchIndex];
if (fieldName == "U")
{
// lookup old U
const volVectorField& dispOldField =
mesh.objectRegistry::lookupObject<volVectorField>(fieldName+"_0");
// subtract old U
masterDU -= dispOldField.boundaryField()[masterPatchIndex];
slaveDU -= dispOldField.boundaryField()[slavePatchIndex];
}
else if (fieldName != "DU")
{
FatalError << "iterativePenaltyFunction::correct()\n"
" The displacement field must be called U or DU"
<< exit(FatalError);
}
// put local masterDU into globalMasterDU
const label masterPatchStart
= mesh.boundaryMesh()[masterPatchIndex].start();
forAll(masterDU, i)
{
globalMasterDU
[
mesh.faceZones()[masterFaceZoneID()
].whichFace(masterPatchStart + i)] =
masterDU[i];
}
//- exchange parallel data
// sum because each face is only on one proc
reduce(globalMasterDU, sumOp<vectorField>());
// globalMasterDU is interpolated to the slave
vectorField globalMasterDUInterpToSlave
(slaveFaceZonePatch.size(), vector::zero);
// interpolate DU from master to slave using inverse distance or ggi
if (interpolationMethod == "patchToPatch")
{
PatchToPatchInterpolation<
PrimitivePatch<
face, List, pointField
>, PrimitivePatch<face, List, pointField>
> masterToSlavePatchToPatchInterpolator
(
masterFaceZonePatch, // from zone
slaveFaceZonePatch, // to zone
alg,
dir
);
globalMasterDUInterpToSlave =
masterToSlavePatchToPatchInterpolator.faceInterpolate<vector>
(
globalMasterDU
);
}
else if (interpolationMethod == "ggi")
{
GGIInterpolation<
PrimitivePatch<
face, List, pointField
>, PrimitivePatch< face, List, pointField >
> masterToSlaveGgiInterpolator
(
masterFaceZonePatch, // master zone
slaveFaceZonePatch, // slave zone
tensorField(0),
tensorField(0),
vectorField(0),
0.0,
0.0,
true,
ggiInterpolation::AABB
);
globalMasterDUInterpToSlave =
masterToSlaveGgiInterpolator.masterToSlave
(
globalMasterDU
);
}
else
{
FatalError
<< "iterativePenaltyFunction::correct()\n"
<< "interpolationMethod " << interpolationMethod << " not known\n"
<< "interpolationMethod must be patchToPatch or ggi"
<< exit(FatalError);
}
// now put global back into local
const label slavePatchStart
= mesh.boundaryMesh()[slavePatchIndex].start();
forAll(masterDUInterpToSlave, i)
{
masterDUInterpToSlave[i] =
globalMasterDUInterpToSlave
[
mesh.faceZones()[slaveFaceZoneID()].whichFace(slavePatchStart + i)
];
}
// Now masterDUInterpToSlave should have masterDU interpolated to the slave
// calculate current slave shear traction
const fvPatch& slavePatch = mesh.boundary()[slavePatchIndex];
const fvPatchField<tensor>& gradField =
slavePatch.lookupPatchField<volTensorField, tensor>
("grad("+fieldName+")");
vectorField slaveShearTraction =
(I - sqr(slaveFaceNormals))
&
tractionBoundaryGradient().traction
(
gradField,
fieldName,
slavePatch,
orthotropic,
nonLinear
);
// calculate slave shear displacement increments
const scalarField magSlavePressure = -1.0*(slaveFaceNormals&slavePressure);
const volVectorField& oldSlaveDispField =
mesh.objectRegistry::lookupObject<volVectorField>(fieldName);
const vectorField& oldSlaveDisp =
oldSlaveDispField.boundaryField()[slavePatchIndex];
label numSlipFaces = 0;
label numStickFaces = 0;
scalarField& stickSlip = stickSlipFaces();
// algorithm
// if the face pressure is negative/zero then the friction is zero
// so set valueFrac to zero and traction to zero
// if the face pressure is positive and the shear traction is less
// than fricCoeff*pressure then this is a sticking face so
// set the valueFrac to (I-n^2) and set the disp to remove any
// slip
// if the face pressure is positive and the shear traction is greater
// than fricCoeff*pressure then this is a slipping face so
// set the valueFrac to zero and set the shear traction to
// fricCoeff*pressure in the opposite direction to slip
// if the shear traction on a slipping face is acting in the same
// direction as the slip then this face should not be slipping
// so we make it a sticking face
const scalar maxMagSlavePressure = gMax(magSlavePressure);
forAll(magSlavePressure, faceI)
{
// there can only be a frictional tangential force when there is
// a positive pressure
// if (magSlavePressure[faceI] > SMALL)
if (magSlavePressure[faceI] > 1e-3*maxMagSlavePressure)
{
//scalar slipTrac = frictionCoeff_*magSlavePressure[faceI];
scalar slipTrac =
frictionLawPtr_->slipTraction(magSlavePressure[faceI]);
// slipping faces
if (mag(slaveShearTraction[faceI]) > (0.99*slipTrac) )
{
// direction of shear traction
vector tracDir =
slaveShearTraction[faceI] / mag(slaveShearTraction[faceI]);
// slip is the difference between the master tangential DU
// and slave tangential DU
vector slip =
(I - sqr(slaveFaceNormals[faceI])) &
( slaveDU[faceI] - masterDUInterpToSlave[faceI]);
// if the slip and dir are in the same direction then
// we will make this a
// sticking face
if ((tracDir & slip) > SMALL)
{
//Info << "face " << faceI << " flipping direction" << endl;
numStickFaces++;
stickSlip[faceI] = 2;
// increment the slave shear displacement
// we add an increment of shear disp to the slave faces
// until there is no more slip
slaveDisp_[faceI] =
-1*relaxationFactor_ * slip;
// slaveDisp_[faceI] is the correction to the disp so we
// add on the original disp
slaveDisp_[faceI] += oldSlaveDisp[faceI];
// remove normal component
slaveDisp_[faceI] =
(I-sqr(slaveFaceNormals[faceI])) & slaveDisp_[faceI];
// set slave valueFraction
slaveValueFrac_[faceI] =
relaxationFactor_*(I - sqr(slaveFaceNormals[faceI]))
+ (1.0 - relaxationFactor_)*slaveValueFrac_[faceI];
// update traction as it is passed to the master
slaveTraction_[faceI] =
relaxationFactor_*slaveShearTraction[faceI]
+ (1-relaxationFactor_)*slaveTraction_[faceI];
}
// else we will limit the shear traction to slipTrac
else
{
numSlipFaces++;
stickSlip[faceI] = 1;
// limit shear traction
slaveTraction_[faceI] =
relaxationFactor_*slipTrac*tracDir
+ (1-relaxationFactor_)*slaveTraction_[faceI];
// update slave disp although it is not used for this face
// while slipping
slaveDisp_[faceI] =
(I-sqr(slaveFaceNormals[faceI])) & oldSlaveDisp[faceI];
// relax the slave valueFraction to zero
//slaveValueFrac_[faceI] =
(1.0 - relaxationFactor_)*slaveValueFrac_[faceI];
slaveValueFrac_[faceI] = symmTensor::zero;
}
}
// sticking faces
else
{
numStickFaces++;
stickSlip[faceI] = 2;
// slip is the difference of the tangential DU between
// the master and slave
vector slip =
(I - sqr(slaveFaceNormals[faceI])) &
(slaveDU[faceI] - masterDUInterpToSlave[faceI]);
// increment the slave shear displacement
// we add an increment of shear disp to the slave faces
// until there is no more slip
slaveDisp_[faceI] = -1*relaxationFactor_*slip;
// slaveDisp_[faceI] is the correction to the disp so we
// add on the original disp
slaveDisp_[faceI] += oldSlaveDisp[faceI];
// remove normal component
slaveDisp_[faceI] =
(I-sqr(slaveFaceNormals[faceI])) & slaveDisp_[faceI];
// set slave valueFraction
slaveValueFrac_[faceI] =
relaxationFactor_*(I - sqr(slaveFaceNormals[faceI]))
+ (1.0 - relaxationFactor_)*slaveValueFrac_[faceI];
// update traction as it is passed to the master
slaveTraction_[faceI] =
relaxationFactor_*slaveShearTraction[faceI]
+ (1-relaxationFactor_)*slaveTraction_[faceI];
}
}
// no friction if pressure is negative or zero
else
{
stickSlip[faceI] = 0;
// relax to zero
slaveTraction_[faceI] = (1.0 - relaxationFactor_)*slaveTraction_[faceI];
slaveValueFrac_[faceI] =
(1.0 - relaxationFactor_)*slaveValueFrac_[faceI];
}
}
// correct oscillations
if (oscillationCorr_)
{
correctOscillations(slaveFaceZonePatch);
}
// get global values
// in parallel, the log is poluted with warnings that
// I am getting max of a list of size zero so
// I will get the max of procs which have some
// of the slave faces
//scalar maxMagMasterTraction = gMax(mag(slaveTraction_))
scalar maxMagMasterTraction = 0.0;
if (slaveTraction_.size() > 0)
maxMagMasterTraction = max(mag(slaveTraction_));
reduce(maxMagMasterTraction, maxOp<scalar>());
reduce(numSlipFaces, sumOp<int>());
reduce(numStickFaces, sumOp<int>());
// master writes to contact info file
if (Pstream::master() && (contactIterNum_ % infoFreq_ == 0))
{
OFstream& contactFile = *contactFilePtr_;
int width = 20;
contactFile << mesh.time().value();
contactFile.width(width);
contactFile << contactIterNum_;
contactFile.width(width);
contactFile << relaxationFactor_;
contactFile.width(width);
contactFile << numSlipFaces;
contactFile.width(width);
contactFile << numStickFaces;
contactFile.width(width);
contactFile << maxMagMasterTraction << endl;
}
}