ModLugreFriction Class Reference

#include <friction.h>

Inheritance diagram for ModLugreFriction:

Collaboration diagram for ModLugreFriction:

Public Member Functions
	ModLugreFriction (const doublereal sigma0, const doublereal sigma1, const doublereal sigma2, const doublereal kappa, const BasicScalarFunction *const ff)
void	SetValue (DataManager *pDM, VectorHandler &X, VectorHandler &XP, SimulationEntity::Hints *ph=0, const unsigned int solution_startdof=0)
unsigned int	iGetNumDof (void) const
virtual std::ostream &	DescribeDof (std::ostream &out, const char *prefix="", bool bInitial=false) const
virtual void	DescribeDof (std::vector< std::string > &desc, bool bInitial=false, int i=-1) const
virtual std::ostream &	DescribeEq (std::ostream &out, const char *prefix="", bool bInitial=false) const
virtual void	DescribeEq (std::vector< std::string > &desc, bool bInitial=false, int i=-1) const
DofOrder::Order	GetDofType (unsigned int i) const
DofOrder::Order	GetEqType (unsigned int i) const
doublereal	fc (void) const
void	AssRes (SubVectorHandler &WorkVec, const unsigned int startdof, const unsigned int solution_startdof, const doublereal F, const doublereal v, const VectorHandler &X, const VectorHandler &XP) throw (Elem::ChangedEquationStructure)
void	AssJac (FullSubMatrixHandler &WorkMat, ExpandableRowVector &dfc, const unsigned int startdof, const unsigned int solution_startdof, const doublereal dCoef, const doublereal F, const doublereal v, const VectorHandler &X, const VectorHandler &XP, const ExpandableRowVector &dF, const ExpandableRowVector &dv) const
Public Member Functions inherited from BasicFriction
virtual void	AfterConvergence (const doublereal F, const doublereal v, const VectorHandler &X, const VectorHandler &XP, const unsigned int solution_startdof)
Public Member Functions inherited from SimulationEntity
	SimulationEntity (void)
virtual	~SimulationEntity (void)
virtual bool	bIsValidIndex (unsigned int i) const
virtual Hint *	ParseHint (DataManager *pDM, const char *s) const
virtual void	BeforePredict (VectorHandler &, VectorHandler &, VectorHandler &, VectorHandler &) const
virtual void	AfterPredict (VectorHandler &X, VectorHandler &XP)
virtual void	Update (const VectorHandler &XCurr, const VectorHandler &XPrimeCurr)
virtual void	DerivativesUpdate (const VectorHandler &XCurr, const VectorHandler &XPrimeCurr)
virtual void	Update (const VectorHandler &XCurr, InverseDynamics::Order iOrder)
virtual void	AfterConvergence (const VectorHandler &X, const VectorHandler &XP)
virtual void	AfterConvergence (const VectorHandler &X, const VectorHandler &XP, const VectorHandler &XPP)
virtual unsigned int	iGetNumPrivData (void) const
virtual unsigned int	iGetPrivDataIdx (const char *s) const
virtual doublereal	dGetPrivData (unsigned int i) const
virtual std::ostream &	OutputAppend (std::ostream &out) const
virtual void	ReadInitialState (MBDynParser &HP)

Private Member Functions
doublereal	alpha (const doublereal z, const doublereal v) const
doublereal	alphad_v (const doublereal z, const doublereal v) const
doublereal	alphad_z (const doublereal z, const doublereal v) const
const doublereal	fs (const doublereal &v) const
const doublereal	fsd (const doublereal &v) const

Private Attributes
const doublereal	sigma0
const doublereal	sigma1
const doublereal	sigma2
const doublereal	kappa
const DifferentiableScalarFunction &	fss
doublereal	f

Additional Inherited Members
Public Types inherited from SimulationEntity
typedef std::vector< Hint * >	Hints

Detailed Description

A friction model based on "Dupont Pierre, Hayward, Vincent, Armstrong Brian and Altpeter Friedhelm, Single state elasto-plastic friction models, IEEE Transactions on Automatic Control, scheduled for June 2002"

Definition at line 135 of file friction.h.

Constructor & Destructor Documentation

ModLugreFriction::ModLugreFriction	(	const doublereal	sigma0,
		const doublereal	sigma1,
		const doublereal	sigma2,
		const doublereal	kappa,
		const BasicScalarFunction *const	ff
	)

Definition at line 60 of file friction.cc.

References NO_OP.

                                                     : 
sigma0(s0),
sigma1(s1),
sigma2(s2),
kappa(k),
fss(dynamic_cast<const DifferentiableScalarFunction&>(*ff)),
f(0.)
{
        NO_OP;
}

Member Function Documentation

doublereal ModLugreFriction::alpha ( const doublereal  z, const doublereal  v  ) const

private

Definition at line 138 of file friction.cc.

References fs(), kappa, M_PI, sigma0, sign(), and grad::sin().

Referenced by AssJac().

                                  {
        
        doublereal zss = fs(v)/sigma0;
        doublereal zba = kappa*zss;

        if (sign(v)==sign(z)) {
                if (std::abs(z) <= std::abs(zba)) {
                } else if ((std::abs(zba)<=std::abs(z)) &&
                        (std::abs(z)<=std::abs(zss))) {
                        return 0.5*std::sin(M_PI*sigma0*z/(fs(v)*(1.-kappa))
                                -M_PI*(1.+kappa)/(2*(1.-kappa)))+0.5;
                } else {
                        return 1.;
                }
        }
        return 0.;
};

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doublereal ModLugreFriction::alphad_v ( const doublereal  z, const doublereal  v  ) const

private

Definition at line 157 of file friction.cc.

References grad::cos(), grad::fabs(), fs(), fsd(), kappa, M_PI, grad::pow(), sigma0, and sign().

Referenced by AssJac().

                                  {

        doublereal zss = fs(v)/sigma0;
        doublereal zba = kappa*zss;
        doublereal der;

        if (sign(v)==sign(z)) {
                if (std::fabs(z) <= std::fabs(zba)) {
                        der = 0.;
                } else if ((std::fabs(zba) <= std::fabs(z)) &&
                        (std::fabs(z) <= std::fabs(zss))) {
                        der = -M_PI/2*std::cos(M_PI*sigma0*z/fs(v)/(1.-kappa)
                                -M_PI*(1.+kappa)/2./(1.-kappa))
                                *sigma0*z/std::pow(fs(v),2)/(1.-kappa)
                                *fsd(v);
                } else {
                        der = 0.;
                }
        } else {
                der = 0.;
        }
        return der;
};

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doublereal ModLugreFriction::alphad_z ( const doublereal  z, const doublereal  v  ) const

private

Definition at line 182 of file friction.cc.

References grad::cos(), grad::fabs(), fs(), kappa, M_PI, sigma0, and sign().

Referenced by AssJac().

                                  {
        
        doublereal zss = fs(v)/sigma0;
        doublereal zba = kappa*zss;
        doublereal der;
        
        if (sign(v)==sign(z)) {
                if (std::fabs(z) <= std::fabs(zba)) {
                        der = 0;
                } else if ((std::fabs(zba) <= std::fabs(z)) && 
                        (std::fabs(z) <= std::fabs(zss))) {
                        der = 0.5*M_PI*sigma0/fs(v)/(1.-kappa)
                                *std::cos(M_PI*sigma0*z/fs(v)/(1.-kappa)
                                -M_PI*(1.+kappa)/2./(1.-kappa));
                } else {
                        der = 0;
                }
        } else {
                der = 0;
        }
        return der;
};

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void ModLugreFriction::AssJac ( FullSubMatrixHandler &  WorkMat, ExpandableRowVector &  dfc, const unsigned int  startdof, const unsigned int  solution_startdof, const doublereal  dCoef, const doublereal  F, const doublereal  v, const VectorHandler &  X, const VectorHandler &  XP, const ExpandableRowVector &  dF, const ExpandableRowVector &  dv  ) const

virtual

Compute self jacobian and friction coefficient derivatives

Implements BasicFriction.

Definition at line 224 of file friction.cc.

References ExpandableRowVector::Add(), alpha(), alphad_v(), alphad_z(), fs(), fsd(), FullSubMatrixHandler::IncCoef(), ExpandableRowVector::Link(), ExpandableRowVector::ReDim(), ExpandableRowVector::Set(), sigma0, sigma1, and sigma2.

                                             {

        doublereal z = X(solution_startdof+1);
        //doublereal zp = XP(solution_startdof+1);
/*
 *      attrito
 */
        dfc.ReDim(2);
        dfc.Set(sigma0*dCoef+sigma1, 1, startdof+1);
        dfc.Set(sigma2, 2); dfc.Link(2, &dv);
        
/*
 *      z
 */
        doublereal alph = alpha(z,v);
        doublereal fsc = fs(v);
        WorkMat.IncCoef(startdof+1,startdof+1,-1.);
        WorkMat.IncCoef(startdof+1,startdof+1,
                -alphad_z(z,v)*v*z/fsc*sigma0*dCoef-
                alph*v/fsc*sigma0*dCoef);
        dv.Add(WorkMat,startdof+1,
                1.-
                alphad_v(z,v)*v*z/fsc*sigma0-
                alph*z/fsc*sigma0+
                alph*v*z/(fsc*fsc)*fsd(v)*sigma0);
//      std::cout << alphad_z(z,v) << std::endl;
/*
 *      callback: dfc[] = df/d{F,v,(z+dCoef,zp)}
 */
};

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void ModLugreFriction::AssRes ( SubVectorHandler &  WorkVec, const unsigned int  startdof, const unsigned int  solution_startdof, const doublereal  F, const doublereal  v, const VectorHandler &  X, const VectorHandler &  XP  ) throw ( Elem::ChangedEquationStructure )

virtual

Compute self residual and friction coefficient

Implements BasicFriction.

Definition at line 210 of file friction.cc.

                                                                     {
        doublereal z = X(solution_startdof+1);
        doublereal zp = XP(solution_startdof+1);
        f = sigma0*z + sigma1*zp + sigma2*v;
        WorkVec.IncCoef(startdof+1,zp-v+alpha(z,v)*v*z/fs(v)*sigma0);
};

std::ostream & ModLugreFriction::DescribeDof ( std::ostream &  out, const char *  prefix = "", bool  bInitial = false  ) const

virtual

Implements SimulationEntity.

Definition at line 91 of file friction.cc.

{
        return out << prefix
                << "[1]: ModLugreFriction state" << std::endl;
}

void ModLugreFriction::DescribeDof ( std::vector< std::string > &  desc, bool  bInitial = false, int  i = -1  ) const

virtual

Implements SimulationEntity.

Definition at line 98 of file friction.cc.

References ASSERT.

{
        ASSERT(i == -1 || i == 0);
        desc.resize(1);
        desc[0] = "ModLugreFriction state";
}

std::ostream & ModLugreFriction::DescribeEq ( std::ostream &  out, const char *  prefix = "", bool  bInitial = false  ) const

virtual

Implements SimulationEntity.

Definition at line 106 of file friction.cc.

{
        return out << prefix
                << "[1]: ModLugreFriction equation" << std::endl;
}

void ModLugreFriction::DescribeEq ( std::vector< std::string > &  desc, bool  bInitial = false, int  i = -1  ) const

virtual

Implements SimulationEntity.

Definition at line 113 of file friction.cc.

References ASSERT.

{
        ASSERT(i == -1 || i == 0);
        desc.resize(1);
        desc[0] = "ModLugreFriction equation";
}

doublereal ModLugreFriction::fc ( void  ) const

virtual

Return last computed friction coefficient

Implements BasicFriction.

Definition at line 206 of file friction.cc.

References f.

                                          {
        return f;
};

const doublereal ModLugreFriction::fs ( const doublereal &  v ) const

private

Definition at line 130 of file friction.cc.

References fss, and sign().

Referenced by alpha(), alphad_v(), alphad_z(), and AssJac().

                                                              {
        return fss(std::abs(v))*sign(v);
};

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const doublereal ModLugreFriction::fsd ( const doublereal &  v ) const

private

Definition at line 134 of file friction.cc.

References DifferentiableScalarFunction::ComputeDiff(), fss, and sign().

Referenced by alphad_v(), and AssJac().

                                                               {
        return fss.ComputeDiff(std::abs(v),1)*sign(v);
};

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DofOrder::Order ModLugreFriction::GetDofType ( unsigned int  i ) const

virtual

Implements SimulationEntity.

Definition at line 120 of file friction.cc.

References ASSERTMSGBREAK, DofOrder::DIFFERENTIAL, and iGetNumDof().

                                                               {
        ASSERTMSGBREAK(i<iGetNumDof(), "INDEX ERROR in ModLugreFriction::GetDofType");
        return DofOrder::DIFFERENTIAL;
};

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DofOrder::Order ModLugreFriction::GetEqType ( unsigned int  i ) const

virtual

Reimplemented from SimulationEntity.

Definition at line 125 of file friction.cc.

References ASSERTMSGBREAK, DofOrder::DIFFERENTIAL, and iGetNumDof().

                                                              {
        ASSERTMSGBREAK(i<iGetNumDof(), "INDEX ERROR in ModLugreFriction::GetEqType");
        return DofOrder::DIFFERENTIAL;
};

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unsigned int ModLugreFriction::iGetNumDof ( void  ) const

virtual

Implements SimulationEntity.

Definition at line 86 of file friction.cc.

Referenced by GetDofType(), and GetEqType().

                                                    {
        return 1;
};

void ModLugreFriction::SetValue ( DataManager *  pDM, VectorHandler &  X, VectorHandler &  XP, SimulationEntity::Hints *  ph = 0, const unsigned int  solution_startdof = 0  )

virtual

Set Initial Values

Reimplemented from BasicFriction.

Definition at line 77 of file friction.cc.

References f, VectorHandler::PutCoef(), and sigma0.

{
        X.PutCoef(solution_startdof+1,f/sigma0);
}

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Member Data Documentation

doublereal ModLugreFriction::f

private

Definition at line 142 of file friction.h.

Referenced by fc(), and SetValue().

const DifferentiableScalarFunction& ModLugreFriction::fss

private

Definition at line 141 of file friction.h.

Referenced by fs(), and fsd().

const doublereal ModLugreFriction::kappa

private

Definition at line 140 of file friction.h.

Referenced by alpha(), alphad_v(), and alphad_z().

const doublereal ModLugreFriction::sigma0

private

Definition at line 137 of file friction.h.

Referenced by alpha(), alphad_v(), alphad_z(), AssJac(), and SetValue().

const doublereal ModLugreFriction::sigma1

private

Definition at line 138 of file friction.h.

Referenced by AssJac().

const doublereal ModLugreFriction::sigma2

private

Definition at line 139 of file friction.h.

Referenced by AssJac().

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The documentation for this class was generated from the following files:

• friction.h
• friction.cc