Description

Class for the basic properties of elastoplastic materials of Drucker-Prager type, that are useful for simulating soils.

#include <ChContinuumMaterial.h>

Inheritance diagram for chrono::fea::ChContinuumDruckerPrager:

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Collaboration diagram for chrono::fea::ChContinuumDruckerPrager:

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Public Member Functions
	ChContinuumDruckerPrager (double young=10000000, double poisson=0.4, double density=1000, double elastic_yield=0.1, double alpha=0.5, double dilatancy=0)
	Create a continuum isotropic Drucker-Prager material.

	ChContinuumDruckerPrager (const ChContinuumDruckerPrager &other)

void	SetElasticYield (double elastic_yield)
	Set the D-P yield modulus C, for Drucker-Prager yield. More...

double	GetElasticYield () const
	Get the elastic yield modulus C.

void	SetInternalFriction (double alpha)
	Set the internal friction coefficient A.

double	GetInternalFriction () const
	Get the internal friction coefficient A.

void	SetFromMohrCoulomb (double phi, double cohesion, bool inner_approx=true)
	Set the C and A parameters of the Drucker-Prager model starting from 'practical' values of inner friction angle phi and cohesion, as used in the faceted Mohr-Coulomb model. More...

virtual void	SetPlasticFlowRate (double flow_rate) override
	Set the plastic flow rate multiplier. More...

virtual double	GetPlasticFlowRate () const override
	Get the flow rate multiplier.

void	SetDilatancy (double dilatancy)
	Set the internal dilatation coefficient. More...

double	GetDilatancy () const
	Get the internal dilatation coefficient.

void	SetHardeningLimit (double hl)
	Set the hardening limit (usually a bit larger than yield), or softening.

double	GetHardeningLimit () const
	Get the hardening limit.

void	SetHardeningSpeed (double hl)
	Set the hardening inverse speed coefficient for exponential hardening. More...

double	GetHardeningSpeed () const
	Get the hardening speed.

virtual double	ComputeYieldFunction (const ChStressTensor<> &stress) const override
	Return a scalar value that is 0 on the yield surface, <0 inside (elastic), >0 outside (incompatible->plastic flow).

virtual void	ComputeReturnMapping (ChStrainTensor<> &plasticstrainflow, const ChStrainTensor<> &incrementstrain, const ChStrainTensor<> &lastelasticstrain, const ChStrainTensor<> &lastplasticstrain) const override
	Correct the strain-stress by enforcing that elastic stress must remain on the yield surface. More...

virtual void	ComputePlasticStrainFlow (ChStrainTensor<> &plasticstrainflow, const ChStrainTensor<> &totstrain) const override
	Compute plastic strain flow direction from strain according to Drucker-Prager.

virtual void	ArchiveOut (ChArchiveOut &archive_out) override

virtual void	ArchiveIn (ChArchiveIn &archive_in) override

Public Member Functions inherited from chrono::fea::ChContinuumElastoplastic
	ChContinuumElastoplastic (double young=10000000, double poisson=0.4, double density=1000)

Public Member Functions inherited from chrono::fea::ChContinuumElastic
	ChContinuumElastic (double young=1e7, double poisson=0.4, double density=1000)

	ChContinuumElastic (const ChContinuumElastic &other)

void	SetYoungModulus (double E)
	Set the Young elastic modulus, as the ratio of the uniaxial stress over the uniaxial strain, for hookean materials.

double	GetYoungModulus () const
	Get the Young elastic modulus.

void	SetPoissonRatio (double v)
	Set the Poisson ratio. More...

double	GetPoissonRatio () const
	Get the Poisson ratio, as v=-transverse_strain/axial_strain.

void	SetShearModulus (double G)
	Set the shear modulus G. More...

double	GetShearModulus () const
	Get the shear modulus G.

double	GetLameFirstParam () const
	Get Lame first parameter. More...

double	GetBulkModulus () const
	Get bulk modulus (increase of pressure for decrease of volume).

double	GetPWaveModulus () const
	Get P-wave modulus. More...

void	ComputeStressStrainMatrix ()
	Computes elasticity matrix and stores the value in this->StressStrainMatrix. More...

ChMatrixDynamic &	GetStressStrainMatrix ()
	Get the Elasticity matrix.

void	ComputeElasticStress (ChStressTensor<> &stress, const ChStrainTensor<> &strain) const
	Compute elastic stress from elastic strain. More...

void	ComputeElasticStrain (ChStrainTensor<> &strain, const ChStressTensor<> &stress) const
	Compute elastic strain from elastic stress. More...

void	SetRayleighDampingAlpha (double alpha)
	Set the Rayleigh mass-proportional damping factor alpha. More...

double	GetRayleighDampingAlpha () const
	Set the Rayleigh mass-proportional damping factor alpha.

void	SetRayleighDampingBeta (double beta)
	Set the Rayleigh stiffness-proportional damping factor beta. More...

double	GetRayleighDampingBeta () const
	Set the Rayleigh stiffness-proportional damping factor beta.

Public Member Functions inherited from chrono::fea::ChContinuumMaterial
	ChContinuumMaterial (double density=1000)

	ChContinuumMaterial (const ChContinuumMaterial &other)

void	SetDensity (double density)
	Set the density of the material.

double	GetDensity () const
	Get the density of the material.

Additional Inherited Members
Protected Attributes inherited from chrono::fea::ChContinuumMaterial
double	m_density

Member Function Documentation

◆ ComputeReturnMapping()

void chrono::fea::ChContinuumDruckerPrager::ComputeReturnMapping	(	ChStrainTensor<> &	plasticstrainflow,
		const ChStrainTensor<> &	incrementstrain,
		const ChStrainTensor<> &	lastelasticstrain,
		const ChStrainTensor<> &	lastplasticstrain
	)		const

overridevirtual

Correct the strain-stress by enforcing that elastic stress must remain on the yield surface.

This computes a plastic flow to be added to plastic strain while integrating.

Implements chrono::fea::ChContinuumElastoplastic.

◆ SetDilatancy()

void chrono::fea::ChContinuumDruckerPrager::SetDilatancy ( double dilatancy )

inline

Set the internal dilatation coefficient.

Usually, 0.. < internal friction.

◆ SetElasticYield()

void chrono::fea::ChContinuumDruckerPrager::SetElasticYield ( double elastic_yield )

inline

Set the D-P yield modulus C, for Drucker-Prager yield.

This defines the transition elastic->plastic.

◆ SetFromMohrCoulomb()

void chrono::fea::ChContinuumDruckerPrager::SetFromMohrCoulomb	(	double	phi,
		double	cohesion,
		bool	inner_approx = `true`
	)

Set the C and A parameters of the Drucker-Prager model starting from 'practical' values of inner friction angle phi and cohesion, as used in the faceted Mohr-Coulomb model.

Use the optional parameter inner_approx to set if the faceted Mohr-Coulomb must be approximated with D-P inscribed (default) or circumscribed.

◆ SetHardeningSpeed()

void chrono::fea::ChContinuumDruckerPrager::SetHardeningSpeed ( double hl )

inline

Set the hardening inverse speed coefficient for exponential hardening.

The larger this value, the slower the hardening or softening process that will asymptotically make yield = hardening_limit.

◆ SetPlasticFlowRate()

virtual void chrono::fea::ChContinuumDruckerPrager::SetPlasticFlowRate ( double flow_rate )

inlineoverridevirtual

Set the plastic flow rate multiplier.

The lower the value, the slower the plastic flow during dynamic simulations.

Implements chrono::fea::ChContinuumElastoplastic.

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

/builds/uwsbel/chrono/src/chrono/fea/ChContinuumMaterial.h
/builds/uwsbel/chrono/src/chrono/fea/ChContinuumMaterial.cpp

Description

Public Member Functions

Additional Inherited Members

Member Function Documentation

◆ ComputeReturnMapping()

◆ SetDilatancy()

◆ SetElasticYield()

◆ SetFromMohrCoulomb()

◆ SetHardeningSpeed()

◆ SetPlasticFlowRate()