Hertz Model Implementation
See this page for the documentation of this contact model.
contactmodelhertz.h
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 | #pragma once
// contactmodelhertz.h
#include "contactmodel/src/contactmodelmechanical.h"
#ifdef HERTZ_LIB
# define HERTZ_EXPORT EXPORT_TAG
#elif defined(NO_MODEL_IMPORT)
# define HERTZ_EXPORT
#else
# define HERTZ_EXPORT IMPORT_TAG
#endif
namespace cmodelsxd {
using namespace itasca;
class ContactModelHertz : public ContactModelMechanical {
public:
enum PropertyKeys { kwHzShear=1
, kwHzPoiss
, kwFric
, kwHzAlpha
, kwHzS
, kwHzSd
, kwHzF
, kwDpNRatio
, kwDpSRatio
, kwDpMode
, kwDpF
, kwDpAlpha
, kwRGap
};
HERTZ_EXPORT ContactModelHertz();
HERTZ_EXPORT virtual ~ContactModelHertz();
virtual void copy(const ContactModel *c);
virtual void archive(ArchiveStream &);
virtual QString getName() const { return "hertz"; }
virtual void setIndex(int i) { index_=i;}
virtual int getIndex() const {return index_;}
virtual QString getProperties() const {
return "hz_shear"
",hz_poiss"
",fric"
",hz_alpha"
",hz_slip"
",hz_mode"
",hz_force"
",dp_nratio"
",dp_sratio"
",dp_mode"
",dp_force"
",dp_alpha"
",rgap"
;
}
enum EnergyKeys { kwEStrain=1,kwESlip,kwEDashpot};
virtual QString getEnergies() const { return "energy-strain,energy-slip,energy-dashpot";}
virtual double getEnergy(uint i) const; // Base 1
virtual bool getEnergyAccumulate(uint i) const; // Base 1
virtual void setEnergy(uint i,const double &d); // Base 1
virtual void activateEnergy() { if (energies_) return; energies_ = NEWC(Energies());}
virtual bool getEnergyActivated() const {return (energies_ !=0);}
enum FishCallEvents { fActivated=0, fSlipChange};
virtual QString getFishCallEvents() const { return "contact_activated,slip_change"; }
virtual QVariant getProperty(uint i,const IContact *) const;
virtual bool getPropertyGlobal(uint i) const;
virtual bool setProperty(uint i,const QVariant &v,IContact *);
virtual bool getPropertyReadOnly(uint i) const;
virtual bool supportsInheritance(uint i) const;
virtual bool getInheritance(uint i) const { assert(i<32); quint32 mask = to<quint32>(1 << i); return (inheritanceField_ & mask) ? true : false; }
virtual void setInheritance(uint i,bool b) { assert(i<32); quint32 mask = to<quint32>(1 << i); if (b) inheritanceField_ |= mask; else inheritanceField_ &= ~mask; }
virtual uint getMinorVersion() const;
virtual bool validate(ContactModelMechanicalState *state,const double ×tep);
virtual bool endPropertyUpdated(const QString &name,const IContactMechanical *c);
virtual bool forceDisplacementLaw(ContactModelMechanicalState *state,const double ×tep);
virtual DVect2 getEffectiveTranslationalStiffness() const { return effectiveTranslationalStiffness_;}
virtual DAVect getEffectiveRotationalStiffness() const { return DAVect(0.0);}
virtual ContactModelHertz *clone() const { return NEWC(ContactModelHertz()); }
virtual double getActivityDistance() const {return rgap_;}
virtual bool isOKToDelete() const { return !isBonded(); }
virtual void resetForcesAndMoments() { hz_F(DVect(0.0)); dp_F(DVect(0.0)); if (energies_) energies_->estrain_ = 0.0; }
virtual void setForce(const DVect &v,IContact *c);
virtual void setArea(const double &) { throw Exception("The setArea method cannot be used with the Hertz contact model."); }
virtual bool checkActivity(const double &gap) { return gap <= rgap_; }
virtual bool isSliding() const { return hz_slip_; }
virtual bool isBonded() const { return false; }
virtual void propagateStateInformation(IContactModelMechanical* oldCm,const CAxes &oldSystem=CAxes(),const CAxes &newSystem=CAxes());
virtual void setNonForcePropsFrom(IContactModel *oldCM);
const double & hz_shear() const {return hz_shear_;}
void hz_shear(const double &d) {hz_shear_=d;}
const double & hz_poiss() const {return hz_poiss_;}
void hz_poiss(const double &d) {hz_poiss_=d;}
const double & fric() const {return fric_;}
void fric(const double &d) {fric_=d;}
uint hz_mode() const {return hz_mode_;}
void hz_mode(uint i) {hz_mode_=i;}
const double & hz_alpha() const {return hz_alpha_;}
void hz_alpha(const double &d) {hz_alpha_=d;}
const DVect & hz_F() const {return hz_F_;}
void hz_F(const DVect &f) { hz_F_=f;}
bool hz_S() const {return hz_slip_;}
void hz_S(bool b) { hz_slip_=b;}
const double & hn() const {return hn_;}
void hn(const double &d) {hn_=d;}
const double & hs() const {return hs_;}
void hs(const double &d) {hs_=d;}
const double & rgap() const {return rgap_;}
void rgap(const double &d) {rgap_=d;}
bool hasDamping() const {return dpProps_ ? true : false;}
double dp_nratio() const {return (hasDamping() ? (dpProps_->dp_nratio_) : 0.0);}
void dp_nratio(const double &d) { if(!hasDamping()) return; dpProps_->dp_nratio_=d;}
double dp_sratio() const {return hasDamping() ? dpProps_->dp_sratio_: 0.0;}
void dp_sratio(const double &d) { if(!hasDamping()) return; dpProps_->dp_sratio_=d;}
int dp_mode() const {return hasDamping() ? dpProps_->dp_mode_: -1;}
void dp_mode(int i) { if(!hasDamping()) return; dpProps_->dp_mode_=i;}
DVect dp_F() const {return hasDamping() ? dpProps_->dp_F_: DVect(0.0);}
void dp_F(const DVect &f) { if(!hasDamping()) return; dpProps_->dp_F_=f;}
double dp_alpha() const {return hasDamping() ? dpProps_->dp_alpha_: 0.0;}
void dp_alpha(const double &d) { if(!hasDamping()) return; dpProps_->dp_alpha_=d;}
bool hasEnergies() const {return energies_ ? true:false;}
double estrain() const {return hasEnergies() ? energies_->estrain_: 0.0;}
void estrain(const double &d) { if(!hasEnergies()) return; energies_->estrain_=d;}
double eslip() const {return hasEnergies() ? energies_->eslip_: 0.0;}
void eslip(const double &d) { if(!hasEnergies()) return; energies_->eslip_=d;}
double edashpot() const {return hasEnergies() ? energies_->edashpot_: 0.0;}
void edashpot(const double &d) { if(!hasEnergies()) return; energies_->edashpot_=d;}
uint inheritanceField() const {return inheritanceField_;}
void inheritanceField(uint i) {inheritanceField_ = i;}
const DVect2 & effectiveTranslationalStiffness() const {return effectiveTranslationalStiffness_;}
void effectiveTranslationalStiffness(const DVect2 &v ) {effectiveTranslationalStiffness_=v;}
/// Return the total force that the contact model holds.
virtual DVect getForce(const IContactMechanical *) const;
/// Return the total moment on 1 that the contact model holds
virtual DAVect getMomentOn1(const IContactMechanical *) const;
/// Return the total moment on 1 that the contact model holds
virtual DAVect getMomentOn2(const IContactMechanical *) const;
private:
static int index_;
bool updateStiffCoef(const IContactMechanical *con);
bool updateEndStiffCoef(const IContactMechanical *con);
bool updateEndFric(const IContactMechanical *con);
void updateEffectiveStiffness(ContactModelMechanicalState *state);
void setDampCoefficients(const ContactModelMechanicalState &state,double *vcn,double *vcs);
// inheritance fields
quint32 inheritanceField_;
// hertz model
double hz_shear_; // Shear modulus
double hz_poiss_; // Poisson ratio
double fric_; // Coulomb friction coefficient
double hz_alpha_; // Exponent
bool hz_slip_; // the current sliding state
uint hz_mode_; // specifies down-scaling of the shear force when normal unloading occurs
DVect hz_F_; // Force carried in the hertz model
double rgap_; // Reference gap
//viscous model
struct dpProps {
dpProps() : dp_nratio_(0.0), dp_sratio_(0.0), dp_mode_(0), dp_F_(DVect(0.0)),dp_alpha_(0.0) {}
double dp_nratio_; // normal viscous critical damping ratio
double dp_sratio_; // shear viscous critical damping ratio
int dp_mode_; // for viscous mode (0-4) 0 = dashpots, 1 = tensile limit, 2 = shear limit, 3 = limit both
DVect dp_F_; // Force in the dashpots
double dp_alpha_; // exponent
};
dpProps * dpProps_;
// energies
struct Energies {
Energies() : estrain_(0.0), eslip_(0.0),edashpot_(0.0) {}
double estrain_; // elastic energy stored in contact
double eslip_; // work dissipated by friction
double edashpot_; // work dissipated by dashpots
};
Energies * energies_;
double hn_; // normal stiffness coefficient
double hs_; // shear stiffness coefficient
DVect2 effectiveTranslationalStiffness_; // effective stiffness
};
} // namespace cmodelsxd
// EoF
|
contactmodelhertz.cpp
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#include "contactmodelhertz.h"
#include "module/interface/icontactmechanical.h"
#include "module/interface/icontact.h"
#include "module/interface/ipiecemechanical.h"
#include "module/interface/ipiece.h"
#include "../version.txt"
#include "module/interface/ifishcalllist.h"
#include "utility/src/tptr.h"
#include "shared/src/mathutil.h"
#include "kernel/interface/iprogram.h"
#include "module/interface/icontactthermal.h"
#include "contactmodel/src/contactmodelthermal.h"
#ifdef HERTZ_LIB
int __stdcall DllMain(void *,unsigned, void *) {
return 1;
}
extern "C" EXPORT_TAG const char *getName() {
#if DIM==3
return "contactmodelmechanical3dhertz";
#else
return "contactmodelmechanical2dhertz";
#endif
}
extern "C" EXPORT_TAG unsigned getMajorVersion() {
return MAJOR_VERSION;
}
extern "C" EXPORT_TAG unsigned getMinorVersion() {
return MINOR_VERSION;
}
extern "C" EXPORT_TAG void *createInstance() {
cmodelsxd::ContactModelHertz *m = NEWC(cmodelsxd::ContactModelHertz());
return (void *)m;
}
#endif // HERTZ_LIB
namespace cmodelsxd {
static const quint32 shearMask = 0x00002;
static const quint32 poissMask = 0x00004;
static const quint32 fricMask = 0x00008;
using namespace itasca;
int ContactModelHertz::index_ = -1;
UInt ContactModelHertz::getMinorVersion() const { return MINOR_VERSION;}
ContactModelHertz::ContactModelHertz() : inheritanceField_(shearMask|poissMask|fricMask)
, hz_shear_(0.0)
, hz_poiss_(0.0)
, fric_(0.0)
, hz_alpha_(1.5)
, hz_slip_(false)
, hz_mode_(0)
, hz_F_(DVect(0.0))
, rgap_(0.0)
, dpProps_(0)
, energies_(0)
, hn_(0.0)
, hs_(0.0)
, effectiveTranslationalStiffness_(DVect2(0.0))
{
}
ContactModelHertz::~ContactModelHertz() {
if (dpProps_)
delete dpProps_;
if (energies_)
delete energies_;
}
void ContactModelHertz::archive(ArchiveStream &stream) {
stream & hz_shear_;
stream & hz_poiss_;
stream & fric_;
stream & hz_alpha_;
stream & hz_slip_;
stream & hz_mode_;
stream & hz_F_;
stream & hn_;
stream & hs_;
if (stream.getArchiveState()==ArchiveStream::Save) {
bool b = false;
if (dpProps_) {
b = true;
stream & b;
stream & dpProps_->dp_nratio_;
stream & dpProps_->dp_sratio_;
stream & dpProps_->dp_mode_;
stream & dpProps_->dp_F_;
stream & dpProps_->dp_alpha_;
} else
stream & b;
b = false;
if (energies_) {
b = true;
stream & b;
stream & energies_->estrain_;
stream & energies_->eslip_;
stream & energies_->edashpot_;
} else
stream & b;
} else {
bool b(false);
stream & b;
if (b) {
if (!dpProps_)
dpProps_ = NEWC(dpProps());
stream & dpProps_->dp_nratio_;
stream & dpProps_->dp_sratio_;
stream & dpProps_->dp_mode_;
stream & dpProps_->dp_F_;
if (stream.getRestoreVersion() >= 2)
stream & dpProps_->dp_alpha_;
}
stream & b;
if (b) {
if (!energies_)
energies_ = NEWC(Energies());
stream & energies_->estrain_;
stream & energies_->eslip_;
stream & energies_->edashpot_;
}
}
stream & inheritanceField_;
stream & effectiveTranslationalStiffness_;
if (stream.getArchiveState()==ArchiveStream::Save || stream.getRestoreVersion() >= 2)
stream & rgap_;
}
void ContactModelHertz::copy(const ContactModel *cm) {
ContactModelMechanical::copy(cm);
const ContactModelHertz *in = dynamic_cast<const ContactModelHertz*>(cm);
if (!in) throw std::runtime_error("Internal error: contact model dynamic cast failed.");
hz_shear(in->hz_shear());
hz_poiss(in->hz_poiss());
fric(in->fric());
hz_alpha(in->hz_alpha());
hz_S(in->hz_S());
hz_mode(in->hz_mode());
hz_F(in->hz_F());
hn(in->hn());
hs(in->hs());
rgap(in->rgap());
if (in->hasDamping()) {
if (!dpProps_)
dpProps_ = NEWC(dpProps());
dp_nratio(in->dp_nratio());
dp_sratio(in->dp_sratio());
dp_mode(in->dp_mode());
dp_F(in->dp_F());
dp_alpha(in->dp_alpha());
}
if (in->hasEnergies()) {
if (!energies_)
energies_ = NEWC(Energies());
estrain(in->estrain());
eslip(in->eslip());
edashpot(in->edashpot());
}
inheritanceField(in->inheritanceField());
effectiveTranslationalStiffness(in->effectiveTranslationalStiffness());
}
QVariant ContactModelHertz::getProperty(uint i,const IContact *) const {
QVariant var;
switch (i) {
case kwHzShear: return hz_shear_;
case kwHzPoiss: return hz_poiss_;
case kwFric: return fric_;
case kwHzAlpha: return hz_alpha_;
case kwHzS: return hz_slip_;
case kwHzSd: return hz_mode_;
case kwHzF: var.setValue(hz_F_); return var;
case kwRGap: return rgap_;
case kwDpNRatio: return dpProps_ ? dpProps_->dp_nratio_ : 0.0;
case kwDpSRatio: return dpProps_ ? dpProps_->dp_sratio_ : 0.0;
case kwDpMode: return dpProps_ ? dpProps_->dp_mode_ : 0;
case kwDpAlpha: return dpProps_ ? dpProps_->dp_alpha_ : 0.0;
case kwDpF:{
dpProps_ ? var.setValue(dpProps_->dp_F_) : var.setValue(DVect(0.0));
return var;
}
}
assert(0);
return QVariant();
}
bool ContactModelHertz::getPropertyGlobal(uint i) const {
switch (i) {
case kwHzF: // fall through
case kwDpF: return false;
}
return true;
}
bool ContactModelHertz::setProperty(uint i,const QVariant &v,IContact *) {
dpProps dp;
switch (i) {
case kwHzShear: {
if (!v.canConvert<double>())
throw Exception("hz_shear must be a double.");
double val(v.toDouble());
if (val<0.0)
throw Exception("Negative shear modulus (hz_shear) not allowed.");
hz_shear_ = val;
return true;
}
case kwHzPoiss: {
if (!v.canConvert<double>())
throw Exception("hz_poiss must be a double.");
double val(v.toDouble());
if (val<=-1.0 || val>0.5)
throw Exception("Poisson ratio (hz_poiss) must be in range (-1.0,0.5].");
hz_poiss_ = val;
return true;
}
case kwFric: {
if (!v.canConvert<double>())
throw Exception("fric must be a double.");
double val(v.toDouble());
if (val<0.0)
throw Exception("Negative fric not allowed.");
fric_ = val;
return false;
}
case kwHzAlpha: {
if (!v.canConvert<double>())
throw Exception("hz_alpha must be a double.");
double val(v.toDouble());
if (val<=0.0)
throw Exception("Negative exponent value not allowed.");
hz_alpha_ = val;
return false;
}
case kwHzSd: {
if (!v.canConvert<uint>())
throw Exception("hz_mode must be 0 or 1.");
uint val(v.toUInt());
if (val >1)
throw Exception("hz_mode must be 0 or 1.");
hz_mode_ = val;
return false;
}
case kwRGap: {
if (!v.canConvert<double>())
throw Exception("Reference gap must be a double.");
double val(v.toDouble());
rgap_ = val;
return false;
}
case kwDpNRatio: {
if (!v.canConvert<double>())
throw Exception("dp_nratio must be a double.");
double val(v.toDouble());
if (val<0.0)
throw Exception("Negative dp_nratio not allowed.");
if (val == 0.0 && !dpProps_)
return false;
if (!dpProps_)
dpProps_ = NEWC(dpProps());
dpProps_->dp_nratio_ = val;
return true;
}
case kwDpSRatio: {
if (!v.canConvert<double>())
throw Exception("dp_sratio must be a double.");
double val(v.toDouble());
if (val<0.0)
throw Exception("Negative dp_sratio not allowed.");
if (val == 0.0 && !dpProps_)
return false;
if (!dpProps_)
dpProps_ = NEWC(dpProps());
dpProps_->dp_sratio_ = val;
return true;
}
case kwDpMode: {
if (!v.canConvert<int>())
throw Exception("The viscous mode dp_mode must be 0, 1, 2, or 3.");
int val(v.toInt());
if (val == 0 && !dpProps_)
return false;
if (val < 0 || val > 3)
throw Exception("The viscous mode dp_mode must be 0, 1, 2, or 3.");
if (!dpProps_)
dpProps_ = NEWC(dpProps());
dpProps_->dp_mode_ = val;
return false;
}
case kwDpAlpha: {
if (!v.canConvert<double>())
throw Exception("dp_alpha must be a double.");
double val(v.toDouble());
if (val<0.0)
throw Exception("Negative dp_alpha not allowed.");
if (val == 0.0 && !dpProps_)
return false;
if (!dpProps_)
dpProps_ = NEWC(dpProps());
dpProps_->dp_alpha_ = val;
return true;
}
case kwHzF: {
if (!v.canConvert<DVect>())
throw Exception("hz_force must be a vector.");
DVect val(v.value<DVect>());
hz_F_ = val;
return false;
}
}
return false;
}
bool ContactModelHertz::getPropertyReadOnly(uint i) const {
switch (i) {
// case kwHzF:
case kwDpF:
case kwHzS:
return true;
default:
break;
}
return false;
}
bool ContactModelHertz::supportsInheritance(uint i) const {
switch (i) {
case kwHzShear:
case kwHzPoiss:
case kwFric:
return true;
default:
break;
}
return false;
}
double ContactModelHertz::getEnergy(uint i) const {
double ret(0.0);
if (!energies_)
return ret;
switch (i) {
case kwEStrain: return energies_->estrain_;
case kwESlip: return energies_->eslip_;
case kwEDashpot: return energies_->edashpot_;
}
assert(0);
return ret;
}
bool ContactModelHertz::getEnergyAccumulate(uint i) const {
switch (i) {
case kwEStrain: return false;
case kwESlip: return true;
case kwEDashpot: return true;
}
assert(0);
return false;
}
void ContactModelHertz::setEnergy(uint i,const double &d) {
if (!energies_) return;
switch (i) {
case kwEStrain: energies_->estrain_ = d; return;
case kwESlip: energies_->eslip_ = d; return;
case kwEDashpot: energies_->edashpot_= d; return;
}
assert(0);
return;
}
bool ContactModelHertz::validate(ContactModelMechanicalState *state,const double &) {
assert(state);
const IContactMechanical *c = state->getMechanicalContact();
assert(c);
if (state->trackEnergy_)
activateEnergy();
updateStiffCoef(c);
if ((inheritanceField_ & shearMask) || (inheritanceField_ & poissMask))
updateEndStiffCoef(c);
if (inheritanceField_ & fricMask)
updateEndFric(c);
updateEffectiveStiffness(state);
return checkActivity(state->gap_);
}
bool ContactModelHertz::updateStiffCoef(const IContactMechanical *con) {
double hnold = hn_;
double hsold = hs_;
double c12 = con->getEnd1Curvature().y();
double c22 = con->getEnd2Curvature().y();
double reff = c12+c22;
if (reff == 0.0)
throw Exception("Hertz contact model undefined for 2 non-curved surfaces");
reff = 2.0 /reff;
hn_ = 2.0/3.0 * (hz_shear_/(1 -hz_poiss_)) * sqrt(2.0*reff);
hs_ = (2.0*(1-hz_poiss_)/(2.0- hz_poiss_))*hz_alpha_*pow(hn_,1.0/hz_alpha_);
return ( (hn_ != hnold) || (hs_ != hsold) );
}
static const QString gstr("hz_shear");
static const QString nustr("hz_poiss");
bool ContactModelHertz::updateEndStiffCoef(const IContactMechanical *con) {
assert(con);
double g1 = hz_shear_;
double g2 = hz_shear_;
double nu1 = hz_poiss_;
double nu2 = hz_poiss_;
QVariant vg1 = con->getEnd1()->getProperty(gstr);
QVariant vg2 = con->getEnd2()->getProperty(gstr);
QVariant vnu1 = con->getEnd1()->getProperty(nustr);
QVariant vnu2 = con->getEnd2()->getProperty(nustr);
if (vg1.isValid() && vg2.isValid()) {
g1 = vg1.toDouble();
g2 = vg2.toDouble();
if (g1 < 0.0 || g2 < 0.0)
throw Exception("Negative shear modulus not allowed in Hertz contact model");
}
if (vnu1.isValid() && vnu2.isValid()) {
nu1 = vnu1.toDouble();
nu2 = vnu2.toDouble();
if (nu1 <= -1.0 || nu1 > 0.5 || nu2 <= -1.0 || nu2 > 0.5)
throw Exception("Poisson ratio should be in range (-1.0,0.5] in Hertz contact model");
}
if (g1*g2 == 0.0) return false;
double es = 1.0 / ((1.0-nu1) / (2.0*g1) + (1.0-nu2) / (2.0*g2));
double gs = 1.0 / ((2.0-nu1) / g1 + (2.0-nu2) /g2);
hz_poiss_ = (4.0*gs-es)/(2.0*gs-es);
hz_shear_ = 2.0*gs*(2-hz_poiss_);
if (hz_shear_ < 0.0)
throw Exception("Negative shear modulus not allowed in Hertz contact model");
if (hz_poiss_ <= -1.0 || hz_poiss_ > 0.5)
throw Exception("Poisson ratio should be in range (-1.0,0.5] in Hertz contact model");
return updateStiffCoef(con);
}
static const QString fricstr("fric");
bool ContactModelHertz::updateEndFric(const IContactMechanical *con) {
assert(con);
QVariant v1 = con->getEnd1()->getProperty(fricstr);
QVariant v2 = con->getEnd2()->getProperty(fricstr);
if (!v1.isValid() || !v2.isValid())
return false;
double fric1 = std::max(0.0,v1.toDouble());
double fric2 = std::max(0.0,v2.toDouble());
double val = fric_;
fric_ = std::min(fric1,fric2);
return ( (fric_ != val) );
}
bool ContactModelHertz::endPropertyUpdated(const QString &name,const IContactMechanical *c) {
assert(c);
QStringList availableProperties = getProperties().simplified().replace(" ","").split(",",QString::SkipEmptyParts);
QRegExp rx(name,Qt::CaseInsensitive);
int idx = availableProperties.indexOf(rx)+1;
bool ret=false;
if (idx<=0)
return ret;
switch(idx) {
case kwHzShear: {
if (inheritanceField_ & shearMask)
ret = updateEndStiffCoef(c);
break;
}
case kwHzPoiss: {
if (inheritanceField_ & poissMask)
ret = updateEndStiffCoef(c);
break;
}
case kwFric: {
if (inheritanceField_ & fricMask)
ret = updateEndFric(c);
break;
}
}
return ret;
}
void ContactModelHertz::updateEffectiveStiffness(ContactModelMechanicalState *state) {
effectiveTranslationalStiffness_ = DVect2(hn_,hs_);
double overlap = rgap_ - state->gap_;
if (overlap <= 0.0) return;
double kn = hz_alpha_*hn_*pow(overlap,hz_alpha_-1.0);
double ks = hs_ * pow(hz_F_.x(),(hz_alpha_-1.0)/hz_alpha_);
DVect2 ret(kn,ks);
// correction if viscous damping active
if (dpProps_) {
DVect2 correct(1.0);
if (dpProps_->dp_nratio_)
correct.rx() = sqrt(1.0+dpProps_->dp_nratio_*dpProps_->dp_nratio_) - dpProps_->dp_nratio_;
if (dpProps_->dp_sratio_)
correct.ry() = sqrt(1.0+dpProps_->dp_sratio_*dpProps_->dp_sratio_) - dpProps_->dp_sratio_;
ret /= (correct*correct);
}
effectiveTranslationalStiffness_ = ret;
}
bool ContactModelHertz::forceDisplacementLaw(ContactModelMechanicalState *state,const double ×tep) {
assert(state);
if (state->activated()) {
if (cmEvents_[fActivated] >= 0) {
FArray<QVariant,2> arg;
QVariant v;
IContact * c = const_cast<IContact*>(state->getContact());
TPtr<IThing> t(c->getIThing());
v.setValue(t);
arg.push_back(v);
IFishCallList *fi = const_cast<IFishCallList*>(state->getProgram()->findInterface<IFishCallList>());
fi->setCMFishCallArguments(c,arg,cmEvents_[fActivated]);
}
}
double overlap = rgap_ - state->gap_;
DVect trans = state->relativeTranslationalIncrement_;
#ifdef THREED
DVect norm(trans.x(),0.0,0.0);
#else
DVect norm(trans.x(),0.0);
#endif
DAVect ang = state->relativeAngularIncrement_;
// normal force in Hertz part
double fn = hn_*pow(overlap,hz_alpha_);
// tangent normal stiffness
double kn = hz_alpha_ * hn_ * pow(overlap,hz_alpha_-1.0);
// initial tangent shear stiffness
double ks = hs_ * pow(fn,(hz_alpha_- 1.0)/hz_alpha_);
DVect fs_old = hz_F_;
fs_old.rx() = 0.0;
if (hz_mode_ && fn < hz_F_.x()) {
double ks_old = hs_ * pow(hz_F_.x(),(hz_alpha_- 1.0)/hz_alpha_);
double rat = ks/ks_old;
fs_old *= rat;
}
DVect u_s = trans;
u_s.rx() = 0.0;
DVect vec = u_s * ks;
DVect fs = fs_old - vec;
if (state->canFail_) {
// resolve sliding
double crit = fn * fric_;
double sfmag = fs.mag();
if (sfmag > crit) {
double rat = crit / sfmag;
fs *= rat;
if (!hz_slip_ && cmEvents_[fSlipChange] >= 0) {
FArray<QVariant,3> arg;
QVariant p1;
IContact * c = const_cast<IContact*>(state->getContact());
TPtr<IThing> t(c->getIThing());
p1.setValue(t);
arg.push_back(p1);
p1.setValue(0);
arg.push_back(p1);
IFishCallList *fi = const_cast<IFishCallList*>(state->getProgram()->findInterface<IFishCallList>());
fi->setCMFishCallArguments(c,arg,cmEvents_[fSlipChange]);
}
hz_slip_ = true;
} else {
if (hz_slip_) {
if (cmEvents_[fSlipChange] >= 0) {
FArray<QVariant,3> arg;
QVariant p1;
IContact * c = const_cast<IContact*>(state->getContact());
TPtr<IThing> t(c->getIThing());
p1.setValue(t);
arg.push_back(p1);
p1.setValue(1);
arg.push_back(p1);
IFishCallList *fi = const_cast<IFishCallList*>(state->getProgram()->findInterface<IFishCallList>());
fi->setCMFishCallArguments(c,arg,cmEvents_[fSlipChange]);
}
hz_slip_ = false;
}
}
}
hz_F_ = fs ; // total force in hertz part
hz_F_.rx() += fn;
effectiveTranslationalStiffness_ = DVect2(kn,ks);
// 3) Account for dashpot forces
if (dpProps_) {
dpProps_->dp_F_.fill(0.0);
double vcn(0.0), vcs(0.0);
setDampCoefficients(*state,&vcn,&vcs);
double fac = 1.0;
if (dpProps_->dp_alpha_ > 0.0) fac = pow(overlap,dpProps_->dp_alpha_);
// First damp all components
dpProps_->dp_F_ = u_s * (-1.0* vcs*fac) / timestep; // shear component
dpProps_->dp_F_ -= norm * vcn*fac / timestep; // normal component
// Need to change behavior based on the dp_mode
if ((dpProps_->dp_mode_ == 1 || dpProps_->dp_mode_ == 3)) {
// limit the tensile if not bonded
if (dpProps_->dp_F_.x() + hz_F_.x() < 0)
dpProps_->dp_F_.rx() = - hz_F_.rx();
}
if (hz_slip_ && dpProps_->dp_mode_ > 1) {
// limit the shear if not sliding
double dfn = dpProps_->dp_F_.rx();
dpProps_->dp_F_.fill(0.0);
dpProps_->dp_F_.rx() = dfn;
}
// Correct effective translational stiffness
DVect2 correct(1.0);
if (dpProps_->dp_nratio_)
correct.rx() = sqrt(1.0+dpProps_->dp_nratio_*dpProps_->dp_nratio_) - dpProps_->dp_nratio_;
if (dpProps_->dp_sratio_)
correct.ry() = sqrt(1.0+dpProps_->dp_sratio_*dpProps_->dp_sratio_) - dpProps_->dp_sratio_;
effectiveTranslationalStiffness_ /= (correct*correct);
}
// 5) Compute energies
if (state->trackEnergy_) {
assert(energies_);
energies_->estrain_ = 0.0;
if (kn)
energies_->estrain_ = hz_alpha_*hz_F_.x()*hz_F_.x()/((hz_alpha_+1.0)*kn);
if (ks) {
double smag2 = fs.mag2();
energies_->estrain_ += 0.5*smag2 / ks;
if (hz_slip_) {
DVect avg_F_s = (fs + fs_old)*0.5;
DVect u_s_el = (fs - fs_old) / ks;
energies_->eslip_ -= std::min(0.0,(avg_F_s | (u_s + u_s_el)));
}
}
if (dpProps_) {
energies_->edashpot_ -= dpProps_->dp_F_ | trans;
}
}
return true;
}
void ContactModelHertz::setForce(const DVect &v,IContact *c) {
hz_F(v);
if (v.x() > 0)
rgap_ = c->getGap() + pow(v.x()/hn_,1./hz_alpha_);
}
void ContactModelHertz::propagateStateInformation(IContactModelMechanical* old,const CAxes &oldSystem,const CAxes &newSystem) {
// Only do something if the contact model is of the same type
if (old->getContactModel()->getName().compare("hertz",Qt::CaseInsensitive) == 0) {
ContactModelHertz *oldCm = (ContactModelHertz *)old;
#ifdef THREED
// Need to rotate just the shear component from oldSystem to newSystem
// Step 1 - rotate oldSystem so that the normal is the same as the normal of newSystem
DVect axis = oldSystem.e1() & newSystem.e1();
double c, ang, s;
DVect re2;
if (!checktol(axis.abs().maxComp(),0.0,1.0,1000)) {
axis = axis.unit();
c = oldSystem.e1()|newSystem.e1();
if (c > 0)
c = std::min(c,1.0);
else
c = std::max(c,-1.0);
ang = acos(c);
s = sin(ang);
double t = 1. - c;
DMatrix<3,3> rm;
rm.get(0,0) = t*axis.x()*axis.x() + c;
rm.get(0,1) = t*axis.x()*axis.y() - axis.z()*s;
rm.get(0,2) = t*axis.x()*axis.z() + axis.y()*s;
rm.get(1,0) = t*axis.x()*axis.y() + axis.z()*s;
rm.get(1,1) = t*axis.y()*axis.y() + c;
rm.get(1,2) = t*axis.y()*axis.z() - axis.x()*s;
rm.get(2,0) = t*axis.x()*axis.z() - axis.y()*s;
rm.get(2,1) = t*axis.y()*axis.z() + axis.x()*s;
rm.get(2,2) = t*axis.z()*axis.z() + c;
re2 = rm*oldSystem.e2();
} else
re2 = oldSystem.e2();
// Step 2 - get the angle between the oldSystem rotated shear and newSystem shear
axis = re2 & newSystem.e2();
DVect2 tpf;
DMatrix<2,2> m;
if (!checktol(axis.abs().maxComp(),0.0,1.0,1000)) {
axis = axis.unit();
c = re2|newSystem.e2();
if (c > 0)
c = std::min(c,1.0);
else
c = std::max(c,-1.0);
ang = acos(c);
if (!checktol(axis.x(),newSystem.e1().x(),1.0,100))
ang *= -1;
s = sin(ang);
m.get(0,0) = c;
m.get(1,0) = s;
m.get(0,1) = -m.get(1,0);
m.get(1,1) = m.get(0,0);
tpf = m*DVect2(oldCm->hz_F_.y(),oldCm->hz_F_.z());
} else {
m.get(0,0) = 1.;
m.get(0,1) = 0.;
m.get(1,0) = 0.;
m.get(1,1) = 1.;
tpf = DVect2(oldCm->hz_F_.y(),oldCm->hz_F_.z());
}
DVect pforce = DVect(0,tpf.x(),tpf.y());
#else
oldSystem;
newSystem;
DVect pforce = DVect(0,oldCm->hz_F_.y());
#endif
for (int i=1; i<dim; ++i)
hz_F_.rdof(i) += pforce.dof(i);
oldCm->hz_F_ = DVect(0.0);
if (dpProps_ && oldCm->dpProps_) {
#ifdef THREED
tpf = m*DVect2(oldCm->dpProps_->dp_F_.y(),oldCm->dpProps_->dp_F_.z());
pforce = DVect(oldCm->dpProps_->dp_F_.x(),tpf.x(),tpf.y());
#else
pforce = oldCm->dpProps_->dp_F_;
#endif
dpProps_->dp_F_ += pforce;
oldCm->dpProps_->dp_F_ = DVect(0.0);
}
if(oldCm->getEnergyActivated()) {
activateEnergy();
energies_->estrain_ = oldCm->energies_->estrain_;
energies_->eslip_ = oldCm->energies_->eslip_;
energies_->edashpot_ = oldCm->energies_->edashpot_;
oldCm->energies_->estrain_ = 0.0;
oldCm->energies_->eslip_ = 0.0;
oldCm->energies_->edashpot_ = 0.0;
}
rgap_ = oldCm->rgap_;
}
}
void ContactModelHertz::setNonForcePropsFrom(IContactModel *old) {
// Only do something if the contact model is of the same type
if (old->getName().compare("hertz",Qt::CaseInsensitive) == 0 && !isBonded()) {
ContactModelHertz *oldCm = (ContactModelHertz *)old;
hn_ = oldCm->hn_;
hs_ = oldCm->hs_;
fric_ = oldCm->fric_;
rgap_ = oldCm->rgap_;
if (oldCm->dpProps_) {
if (!dpProps_)
dpProps_ = NEWC(dpProps());
dpProps_->dp_nratio_ = oldCm->dpProps_->dp_nratio_;
dpProps_->dp_sratio_ = oldCm->dpProps_->dp_sratio_;
dpProps_->dp_mode_ = oldCm->dpProps_->dp_mode_;
}
}
}
DVect ContactModelHertz::getForce(const IContactMechanical *) const {
DVect ret(hz_F_);
if (dpProps_)
ret += dpProps_->dp_F_;
return ret;
}
DAVect ContactModelHertz::getMomentOn1(const IContactMechanical *c) const {
DVect force = getForce(c);
DAVect ret(0.0);
c->updateResultingTorqueOn1Local(force,&ret);
return ret;
}
DAVect ContactModelHertz::getMomentOn2(const IContactMechanical *c) const {
DVect force = getForce(c);
DAVect ret(0.0);
c->updateResultingTorqueOn2Local(force,&ret);
return ret;
}
void ContactModelHertz::setDampCoefficients(const ContactModelMechanicalState &state,double *vcn,double *vcs) {
double overlap = rgap_ - state.gap_;
double kn = hz_alpha_*hn_*pow(overlap,hz_alpha_-1.0);
double ks = hs_ * pow(hz_F_.x(),(hz_alpha_-1.0)/hz_alpha_);
*vcn = dpProps_->dp_nratio_ * 2.0 * sqrt(state.inertialMass_*(kn));
*vcs = dpProps_->dp_sratio_ * 2.0 * sqrt(state.inertialMass_*(ks));
}
} // namespace cmodelsxd
// EoF
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