Hysteretic Model Implementation
See this page for the documentation of this contact model.
contactmodelhysteretic.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 | #pragma once
// contactmodelhysteretic.h
#include "contactmodel/src/contactmodelmechanical.h"
#ifdef HYSTERETIC_LIB
# define HYSTERETIC_EXPORT EXPORT_TAG
#elif defined(NO_MODEL_IMPORT)
# define HYSTERETIC_EXPORT
#else
# define HYSTERETIC_EXPORT IMPORT_TAG
#endif
namespace cmodelsxd {
using namespace itasca;
class ContactModelHysteretic : public ContactModelMechanical {
public:
enum PropertyKeys { kwHzShear=1
, kwHzPoiss
, kwFric
, kwHzF
, kwHzS
, kwHzSd
, kwHzAlpha
, kwDpMode
, kwDpEn
, kwDpEnMin
, kwDpF
};
HYSTERETIC_EXPORT ContactModelHysteretic();
HYSTERETIC_EXPORT virtual ~ContactModelHysteretic();
virtual void copy(const ContactModel *c) override;
virtual void archive(ArchiveStream &);
virtual QString getName() const { return "hysteretic"; }
virtual void setIndex(int i) { index_=i;}
virtual int getIndex() const {return index_;}
virtual QString getProperties() const {
return "hz_shear"
",hz_poiss"
",fric"
",hz_force"
",hz_slip"
",hz_mode"
",hz_alpha"
",dp_mode"
",dp_en"
",dp_enmin"
",dp_force"
;
}
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 ContactModelHysteretic *clone() const override { return NEWC(ContactModelHysteretic()); }
virtual double getActivityDistance() const {return 0.0;}
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 *) { hz_F(v); }
virtual void setArea(const double &) { throw Exception("The setArea method cannot be used with this contact model."); }
virtual double getArea() const { return 0.0; }
virtual bool checkActivity(const double &gap) { return gap <= 0.0; }
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 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 & hz_alpha() const {return hz_alpha_;}
void hz_alpha(const double &d) {hz_alpha_=d;}
int dp_mode() const {return dp_mode_;}
void dp_mode(int i) {dp_mode_=i;}
const double & dp_en() const {return dp_en_;}
void dp_en(const double &d) {dp_en_=d;}
const double & dp_enmin() const {return dp_enmin_;}
void dp_enmin(const double &d) {dp_enmin_=d;}
const DVect & dp_F() const {return dp_F_;}
void dp_F(const DVect &f) { dp_F_=f;}
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 & vni() const {return vni_;}
void vni(const double &d) {vni_=d;}
double pfac() const {return pfac_;}
void pfac(int i) {pfac_=i;}
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);
// inheritance fields
quint32 inheritanceField_;
// hertz model
double hz_shear_; // Shear modulus
double hz_poiss_; // Poisson ratio
double fric_; // Coulomb friction coefficient
DVect hz_F_; // Force carried in the hertz model
bool hz_slip_; // the current sliding state
uint hz_mode_; // specifies down-scaling of the shear force when normal unloading occurs
double hz_alpha_; // alpha exponent
int dp_mode_; // Damping scheme mode
double dp_en_; // normal restitution coefficient
double dp_enmin_; // minimal normal restitution coefficient in default mode
DVect dp_F_; // Damping Force
// 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
double vni_; // normal impact velocity
double pfac_; // previous damping factor
};
} // namespace cmodelsxd
// EoF
|
contactmodelhysteretic.cpp
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#include "contactmodelhysteretic.h"
#include "../version.txt"
#include "contactmodel/src/contactmodelthermal.h"
#include "fish/src/parameter.h"
#include "utility/src/tptr.h"
#include "shared/src/mathutil.h"
#include "module/interface/icontact.h"
#include "module/interface/icontactmechanical.h"
#include "module/interface/icontactthermal.h"
#include "module/interface/ifishcalllist.h"
#include "module/interface/ipiece.h"
#include "module/interface/ipiecemechanical.h"
#include "kernel/interface/iprogram.h"
#ifdef HYSTERETIC_LIB
#ifdef _WIN32
int __stdcall DllMain(void *,unsigned, void *) {
return 1;
}
#endif
extern "C" EXPORT_TAG const char *getName() {
#if DIM==3
return "contactmodelmechanical3dhysteretic";
#else
return "contactmodelmechanical2dhysteretic";
#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::ContactModelHysteretic *m = NEWC(cmodelsxd::ContactModelHysteretic());
return (void *)m;
}
#endif // HYSTERETIC_LIB
namespace cmodelsxd {
static const quint32 shearMask = 0x00002;
static const quint32 poissMask = 0x00004;
static const quint32 fricMask = 0x00008;
using namespace itasca;
int ContactModelHysteretic::index_ = -1;
UInt ContactModelHysteretic::getMinorVersion() const { return MINOR_VERSION;}
ContactModelHysteretic::ContactModelHysteretic() : inheritanceField_(shearMask|poissMask|fricMask)
, hz_shear_(0.0)
, hz_poiss_(0.0)
, fric_(0.0)
, hz_F_(DVect(0.0))
, hz_slip_(false)
, hz_mode_(0)
, hz_alpha_(1.5)
, dp_mode_(0)
, dp_en_(1.0)
, dp_enmin_(0.0)
, dp_F_(DVect(0.0))
, energies_(0)
, hn_(0.0)
, hs_(0.0)
, effectiveTranslationalStiffness_(DVect2(0.0))
, vni_(0.0)
, pfac_(0.0)
{
}
ContactModelHysteretic::~ContactModelHysteretic() {
if (energies_)
delete energies_;
}
void ContactModelHysteretic::archive(ArchiveStream &stream) {
stream & hz_shear_;
stream & hz_poiss_;
stream & fric_;
stream & hz_F_;
stream & hz_slip_;
stream & hz_mode_;
stream & hz_alpha_;
stream & dp_mode_;
stream & dp_en_;
stream & dp_enmin_;
stream & dp_F_;
stream & hn_;
stream & hs_;
stream & vni_;
stream & pfac_;
if (stream.getArchiveState()==ArchiveStream::Save) {
bool 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 (!energies_)
energies_ = NEWC(Energies());
stream & energies_->estrain_;
stream & energies_->eslip_;
stream & energies_->edashpot_;
}
}
stream & inheritanceField_;
stream & effectiveTranslationalStiffness_;
}
void ContactModelHysteretic::copy(const ContactModel *cm) {
ContactModelMechanical::copy(cm);
const ContactModelHysteretic *in = dynamic_cast<const ContactModelHysteretic*>(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_F(in->hz_F());
hz_S(in->hz_S());
hz_mode(in->hz_mode());
hz_alpha(in->hz_alpha());
dp_mode(in->dp_mode());
dp_en(in->dp_en());
dp_enmin(in->dp_enmin());
hn(in->hn());
hs(in->hs());
vni(in->vni());
pfac(in->pfac());
if (in->hasEnergies()) {
if (!energies_)
energies_ = NEWC(Energies());
estrain(in->estrain());
eslip(in->eslip());
edashpot(in->edashpot());
}
inheritanceField(in->inheritanceField());
effectiveTranslationalStiffness(in->effectiveTranslationalStiffness());
}
QVariant ContactModelHysteretic::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 kwHzF: var.setValue(hz_F_); return var;
case kwHzS: return hz_slip_;
case kwHzSd: return hz_mode_;
case kwHzAlpha: return hz_alpha_;
case kwDpMode: return dp_mode_;
case kwDpEn: return dp_en_;
case kwDpEnMin: return dp_enmin_;
case kwDpF: var.setValue(dp_F_); return var;
}
assert(0);
return QVariant();
}
bool ContactModelHysteretic::getPropertyGlobal(uint i) const {
switch (i) {
case kwHzF: return false;
case kwDpF: return false;
}
return true;
}
bool ContactModelHysteretic::setProperty(uint i,const QVariant &v,IContact *) {
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 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 kwHzAlpha: {
if (!v.canConvert<double>())
throw Exception("hz_alpha must be a double.");
double val(v.toDouble());
if (val<0.0)
throw Exception("Alpha exponent (hz_alpha) must be positive.");
hz_alpha_ = val;
return false;
}
case kwDpMode: {
if (!v.canConvert<int>())
throw Exception("dp_mode must be an integer.");
int val(v.toInt());
dp_mode_ = val;
return false;
}
case kwDpEn: {
if (!v.canConvert<double>())
throw Exception("dp_en must be a double.");
double val(v.toDouble());
if (val<0.0 || val>1.0)
throw Exception("Restitution coefficient (dp_en) must be in range [0.0,1.0] ");
dp_en_ = val;
return false;
}
case kwDpEnMin: {
if (!v.canConvert<double>())
throw Exception("dp_enmin must be a double.");
double val(v.toDouble());
if (val<0.0 || val>1.0)
throw Exception("Minimal restitution coefficient (dp_enmin) must be in range [0.0,1.0] ");
dp_enmin_ = val;
return false;
}
}
return false;
}
bool ContactModelHysteretic::getPropertyReadOnly(uint i) const {
switch (i) {
case kwHzF:
case kwHzS:
case kwDpF:
return true;
default:
break;
}
return false;
}
bool ContactModelHysteretic::supportsInheritance(uint i) const {
switch (i) {
case kwHzShear:
case kwHzPoiss:
case kwFric:
return true;
default:
break;
}
return false;
}
double ContactModelHysteretic::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 ContactModelHysteretic::getEnergyAccumulate(uint i) const {
switch (i) {
case kwEStrain: return false;
case kwESlip: return true;
case kwEDashpot: return true;
}
assert(0);
return false;
}
void ContactModelHysteretic::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 ContactModelHysteretic::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 ContactModelHysteretic::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("Hysteretic 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*pow(hz_shear_*hz_shear_*3.0*(1-hz_poiss_)*(reff),1.0/3.0)) / (2.0- hz_poiss_);
return ( (hn_ != hnold) || (hs_ != hsold) );
}
static const QString gstr("hz_shear");
static const QString nustr("hz_poiss");
bool ContactModelHysteretic::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 Hysteretic 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 Hysteretic 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 Hysteretic contact model");
if (hz_poiss_ <= -1.0 || hz_poiss_ > 0.5)
throw Exception("Poisson ratio should be in range (-1.0,0.5] in Hysteretic contact model");
return updateStiffCoef(con);
}
static const QString fricstr("fric");
bool ContactModelHysteretic::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 ContactModelHysteretic::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 ContactModelHysteretic::updateEffectiveStiffness(ContactModelMechanicalState *state) {
effectiveTranslationalStiffness_ = DVect2(hn_,hs_);
if (state->gap_ >= 0.0) return;
double overlap = - state->gap_;
double kn = 1.5*hn_*sqrt(overlap);
double ks = hs_ * pow(hz_F_.x(),(1.0/3.0));
DVect2 ret(kn,ks);
effectiveTranslationalStiffness_ = ret;
}
bool ContactModelHysteretic::forceDisplacementLaw(ContactModelMechanicalState *state,const double ×tep) {
assert(state);
bool firstActive = false;
if (state->activated()) {
if (cmEvents_[fActivated] >= 0) {
auto c = state->getContact();
std::vector<fish::Parameter> arg = { fish::Parameter(c->getIThing()) };
IFishCallList *fi = const_cast<IFishCallList*>(state->getProgram()->findInterface<IFishCallList>());
fi->setCMFishCallArguments(c,arg,cmEvents_[fActivated]);
}
firstActive = true;
}
double overlap = - 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_;
DVect hz_F_old = hz_F_;
hz_F_ = DVect(0.0);
dp_F_ = DVect(0.0);
double ks_old = hs_ * pow(hz_F_old.x(),(1.0/3.0));
DVect fs_old = hz_F_old;
fs_old.rx() = 0.0;
if (overlap > 0) {
double kn = 1.5 * hn_ * sqrt(overlap);
double vn = norm.x() / timestep;
if (firstActive) {
if (vn <= 0.0)
vni_= vn;
else
vni_ = 0.0;
fs_old = DVect(0.0);
ks_old = 0.0;
hz_F_old = DVect(0.0);
pfac_ = 0.0;
}
hz_F_.rx() = hn_*pow(overlap,hz_alpha_);
double ks = hs_ * pow(hz_F_.x(),(1.0/3.0));
effectiveTranslationalStiffness_ = DVect2(kn,ks);
//damping force
if (std::abs(vni_) <= limits<double>::epsilon()*1000.0)
dp_F_.rx() = 0.0;
else {
double ratio = vn/vni_;
double fac(0.0);
switch (dp_mode_) {
default:
{
double used = max(dp_en_,dp_enmin_);
fac = max(0.0,(1.0-used*used)/used)*ratio; //Gonthier et al.
}
break;
case 1:
fac = 0.75*(1.0-dp_en_*dp_en_)*ratio; // Lankarani et al (1989).
break;
case 2:
fac = 0.75*(1.0-dp_en_*dp_en_)*exp(2.0*(1-dp_en_))*ratio; // Zhiying et al.
break;
}
if (fac <= -1.0) { // sucking
if (pfac_ >= 0.0) { //switch in one timestep from pushing to sucking - instability
fac = 0.0;
pfac_ = 0.0;
} else
pfac_ = fac;
} else if (pfac_ != 0.0 && abs(fac) > 10.0*abs(pfac_)) { // growing too fast - instability
fac = 0.0;
pfac_ = 0.0;
} else
pfac_ = fac;
dp_F_.rx() = hz_F_.x()*fac;
}
DVect u_s = trans;
u_s.rx() = 0.0;
DVect vec = u_s * ks;
if (hz_mode_ && (hz_F_.x() < hz_F_old.x())) {
double rat = ks / ks_old;
fs_old *= rat;
}
DVect fs = fs_old - vec;
if (state->canFail_) {
// resolve sliding
double crit = hz_F_.x() * fric_;
double sfmag = fs.mag();
if (sfmag > crit) {
double rat = crit / sfmag;
fs *= rat;
if (!hz_slip_ && cmEvents_[fSlipChange] >= 0) {
auto c = state->getContact();
std::vector<fish::Parameter> arg = { fish::Parameter(c->getIThing()),
fish::Parameter() };
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) {
auto c = state->getContact();
std::vector<fish::Parameter> arg = { fish::Parameter(c->getIThing()),
fish::Parameter((qint64)1) };
IFishCallList *fi = const_cast<IFishCallList*>(state->getProgram()->findInterface<IFishCallList>());
fi->setCMFishCallArguments(c,arg,cmEvents_[fSlipChange]);
}
hz_slip_ = false;
}
}
}
fs.rx() = hz_F_.x();
hz_F_ = fs; // total force in hertz part
// 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)*kn);
if (ks) {
DVect s = hz_F_;
s.rx() = 0.0;
double smag2 = s.mag2();
energies_->estrain_ += 0.5*smag2 / ks;
if (hz_slip_) {
hz_F_old.rx() = 0.0;
DVect avg_F_s = (s + hz_F_old)*0.5;
DVect u_s_el = (s - hz_F_old) / ks;
energies_->eslip_ -= std::min(0.0,(avg_F_s | (u_s + u_s_el)));
}
}
energies_->edashpot_ -= dp_F_ | trans;
}
} else {
hz_F_ = DVect(0.0);
dp_F_ = DVect(0.0);
pfac_ = 0.0;
}
return true;
}
void ContactModelHysteretic::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("hysteretic",Qt::CaseInsensitive) == 0) {
ContactModelHysteretic *oldCm = (ContactModelHysteretic *)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(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;
}
}
}
void ContactModelHysteretic::setNonForcePropsFrom(IContactModel *old) {
// Only do something if the contact model is of the same type
if (old->getName().compare("hysteretic",Qt::CaseInsensitive) == 0 && !isBonded()) {
ContactModelHysteretic *oldCm = (ContactModelHysteretic *)old;
hn_ = oldCm->hn_;
hs_ = oldCm->hs_;
fric_ = oldCm->fric_;
vni_ = oldCm->vni_;
pfac_ = oldCm->pfac_;
}
}
DVect ContactModelHysteretic::getForce(const IContactMechanical *) const {
DVect ret(hz_F_);
ret += dp_F_;
return ret;
}
DAVect ContactModelHysteretic::getMomentOn1(const IContactMechanical *c) const {
DVect force = getForce(c);
DAVect ret(0.0);
c->updateResultingTorqueOn1Local(force,&ret);
return ret;
}
DAVect ContactModelHysteretic::getMomentOn2(const IContactMechanical *c) const {
DVect force = getForce(c);
DAVect ret(0.0);
c->updateResultingTorqueOn2Local(force,&ret);
return ret;
}
} // namespace cmodelsxd
// EoF
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