ElasticRodMaterial Class Reference

Linear elastic rod material with configurable cross-sectional properties.

#include "ElasticRodMaterial.h"

Inheritance diagram for ElasticRodMaterial:

Collaboration diagram for ElasticRodMaterial:

Public Member Functions
	ElasticRodMaterial (const String &name, const Properties &conf, const Properties &props, const Properties &globdat)
	Constructor with configuration and global data.
virtual void	configure (const Properties &props, const Properties &globdat) override
	Configure material properties including cross-sectional geometry.
virtual void	getConfig (const Properties &conf, const Properties &globdat) const override
	Retrieve current material configuration.
virtual Matrix	getMaterialStiff () const override
	Get the material stiffness matrix.
virtual Matrix	getMaterialStiff (const idx_t &ielem, const idx_t &ip) const override
	Get the material stiffness matrix for specific element and integration point.
virtual void	getMaterialStiff (const Matrix &stiff) const override
	Write the material stiffness matrix into an existing matrix (no allocation, for hot code)
virtual void	getMaterialStiff (const Matrix &stiff, const idx_t &ielem, const idx_t &ip) const override
	Write the material stiffness matrix for an element and integration point into an existing matrix.
virtual Matrix	getMaterialMass () const override
	Get the material mass matrix per unit length.
virtual Matrix	getMaterialMass (const idx_t &ielem, const idx_t &ip) const override
	Get the material mass matrix for specific element and integration point.
virtual void	getMaterialMass (const Matrix &mass) const override
	Write the material mass matrix per unit length into an existing matrix (no allocation, for hot code)
virtual void	getMaterialMass (const Matrix &mass, const idx_t &ielem, const idx_t &ip) const override
	Write the material mass matrix for an element and integration point into an existing matrix.
virtual Matrix	getLumpedMass (const double l) const override
	Get the lumped mass matrix for a given element length.
virtual Matrix	getLumpedMass (const double l, const idx_t &ielem) const override
	Get the lumped mass matrix for specific element and length.
virtual void	getStress (const Vector &stress, const Vector &strain) override
	Compute stress vector from strain vector.
virtual void	getStress (const Vector &stress, const Vector &strain, const idx_t &ielem, const idx_t &ip, const bool inelastic=false) override
	Compute stress with element and integration point context.
virtual void	getTable (XTable &strain_table, const Vector &weights, const String &name, const IdxVector &items) const override
	Populate strain table with material-specific data.
virtual void	applyDeform () override
	Apply computed deformation to the material state.
virtual void	rejectDeform () override
	Reject the current deformation and revert to previous state.
virtual double	getDissipatedEnergy (const idx_t &ielem, const idx_t &ip) const override
	Get the dissipated energy at a specific integration point.
virtual double	getPotentialEnergy (const idx_t &ielem, const idx_t &ip) const override
	Get the potential energy at a specific integration point.
virtual double	getHardeningPotential (const idx_t &ielem, const idx_t &ip) const override
	Get the hardening potential energy at a specific integration point.
Public Member Functions inherited from Material
	Material (const String &name, const Properties &conf, const Properties &props, const Properties &globdat)
	Constructs a new Material object.
virtual String	getContext () const override
	Get the context string for error reporting and debugging.

Static Public Member Functions
static Ref< Material >	makeNew (const String &name, const Properties &conf, const Properties &props, const Properties &globdat)
	Factory method for material creation.
static void	declare ()
	Register material type with factory.

Static Public Attributes
Material type and property identifiers
static const char *	TYPE_NAME = "ElasticRod"
static const char *	STIFF_PREFIX = "C_"
	Prefix for direct stiffness-matrix input.
static const char *	YOUNGS_MODULUS = "young"
	Young's modulus property key.
static const char *	SHEAR_MODULUS = "shear_modulus"
	Shear modulus property key.
static const char *	POISSON_RATIO = "poisson_ratio"
	Poisson's ratio property key.
static const char *	AREA = "area"
	Cross-sectional area property key.
static const char *	DENSITY = "density"
	Material density property key.
static const char *	AREA_MOMENT = "area_moment"
	Area moment of inertia property key.
static const char *	SHEAR_FACTOR = "shear_correction"
	Shear correction factor property key.
static const char *	POLAR_MOMENT = "polar_moment"
	Polar moment of inertia property key.
static const char *	CROSS_SECTION = "cross_section"
	Cross-section type property key (e.g., "square", "circle" "rectangle")
static const char *	RADIUS = "radius"
	Radius for circular sections property key.
static const char *	SIDE_LENGTH = "side_length"
	Side lengths for rectangular sections property key.
Element and edge properties
static const char *	N_ELEM = "elemCount"
	Number of elements property key.
static const char *	EDGE_FACTOR = "edge_factor"
	Edge factor f property key: edge elements get stiffness blocks scaled by f^2, f^3, f^4 and mass blocks by (2-f)^2, (2-f)^3, (2-f)^4.
static const char *	EDGE_ELEMS = "edge_elements"
	Number of edge elements property key.
Static Public Attributes inherited from Material
static const char *	VERBOSITY_PROP = "verbosity"
	Property name for verbosity level control.

Protected Member Functions
	~ElasticRodMaterial ()
	Destroy the elastic rod material.
void	calcMaterialStiff_ ()
	Calculate material stiffness matrix.
void	calcMaterialMass_ ()
	Calculate material mass matrix.
Protected Member Functions inherited from Material
virtual	~Material ()
	Destroy the Material object.

Protected Attributes
Material properties
double	young_
	Young's modulus.
double	shearMod_
	Shear modulus.
double	shearParam_
	Shear parameter.
double	edgeFact_
	Edge factor for lattice materials.
idx_t	edgeElems_
	Number of edge elements.
idx_t	nElem_
	Total number of elements.
double	area_
	Cross-sectional area.
Vector	areaMoment_
	Area moments of inertia.
double	polarMoment_
	Polar moment of inertia.
String	crossSection_
	Cross-section type identifier.
double	radius_
	Radius for circular sections.
Vector	sideLength_
	Side lengths for rectangular sections.
double	density_
	Material density.
Computed matrices and state
Matrix	materialK_
	Material stiffness matrix.
Matrix	materialM_
	Material mass matrix.
Cubix	oldStrains_
	Strains from last converged step.
Cubix	currStrains_
	Strains from current iteration.
Matrix	energyPot_
	Potential energy storage.
jem::numeric::MatmulChain< double, 1 >	matvec_
Matrix	stiffWork_
	Work array for the stiffness in getStress and applyDeform.
String	rodName_
	Material instance name.
Protected Attributes inherited from Material
idx_t	verbosity_
	Verbosity level for material output and debugging.

Constructor & Destructor Documentation

ElasticRodMaterial()

ElasticRodMaterial::ElasticRodMaterial	(	const String &	name,
		const Properties &	conf,
		const Properties &	props,
		const Properties &	globdat
	)

Parameters

[in]	name	Material instance name
[out]	conf	Actually used configuration properties
[in]	props	User-specified material properties
[in]	globdat	Global data container

~ElasticRodMaterial()

ElasticRodMaterial::~ElasticRodMaterial ( )

protected

Member Function Documentation

applyDeform()

void ElasticRodMaterial::applyDeform ( )

overridevirtual

This method commits the current deformation state to the material's internal variables. It's typically called at the end of a successful load step to update the material's permanent state.

Implements Material.

Reimplemented in ElastoPlasticRodMaterial.

calcMaterialMass_()

void ElasticRodMaterial::calcMaterialMass_ ( )

protected

calcMaterialStiff_()

void ElasticRodMaterial::calcMaterialStiff_ ( )

protected

configure()

void ElasticRodMaterial::configure ( const Properties &  props, const Properties &  globdat  )

overridevirtual

Parameters

[in]	props	Properties containing configuration parameters
[in]	globdat	Global data container with simulation context

Exceptions

jem::IllegalInputException

if negative material properties are provided

Reimplemented from Material.

Reimplemented in ElastoPlasticRodMaterial.

declare()

void ElasticRodMaterial::declare ( )

static

getConfig()

void ElasticRodMaterial::getConfig ( const Properties &  conf, const Properties &  globdat  ) const

overridevirtual

Parameters

[out]	conf	Properties object to store configuration in
[in]	globdat	Global data container with simulation context

Reimplemented from Material.

Reimplemented in ElastoPlasticRodMaterial.

getDissipatedEnergy()

double ElasticRodMaterial::getDissipatedEnergy ( const idx_t &  ielem, const idx_t &  ip  ) const

overridevirtual

Computes the energy dissipated through inelastic processes at the specified element and integration point location.

Parameters

[in]	ielem	Element index
[in]	ip	Integration point index within the element

Returns

Total dissipated energy at the specified location

Note

Contract: must return the value of the last committed state, i.e. it has to be stored in applyDeform(). SpecialCosseratRodModel::getEnergies_ reads it right after applyDeform() without re-evaluating strains/stresses.

Implements Material.

Reimplemented in ElastoPlasticRodMaterial.

getHardeningPotential()

double ElasticRodMaterial::getHardeningPotential ( const idx_t &  ielem, const idx_t &  ip  ) const

overridevirtual

Computes the energy stored in hardening variables for plasticity models. This represents the energy associated with the evolution of the yield surface.

Parameters

[in]	ielem	Element index
[in]	ip	Integration point index within the element

Returns

Hardening potential energy at the specified location

Implements Material.

Reimplemented in ElastoPlasticRodMaterial.

getLumpedMass() [1/2]

Matrix ElasticRodMaterial::getLumpedMass ( const double  l ) const

overridevirtual

Computes a lumped (diagonal) mass matrix for the given element length.

Parameters

[in]

l

Element length

Returns

Lumped mass matrix for the element

Reimplemented from Material.

getLumpedMass() [2/2]

Matrix ElasticRodMaterial::getLumpedMass ( const double  l, const idx_t &  ielem  ) const

overridevirtual

Default element-specific lumped mass.

Element-specific version of lumped mass computation.

Parameters

[in]	l	Element length
[in]	ielem	Element index for potential customization

Returns

Lumped mass matrix for the specified element

Reimplemented from Material.

getMaterialMass() [1/4]

Matrix ElasticRodMaterial::getMaterialMass ( ) const

overridevirtual

Computes the material mass density matrix used in dynamic analysis. The translational part of the mass matrix is typically diagonal with density values.

Returns

Mass matrix per unit length

Implements Material.

getMaterialMass() [2/4]

Matrix ElasticRodMaterial::getMaterialMass ( const idx_t &  ielem, const idx_t &  ip  ) const

overridevirtual

Default element-specific mass matrix.

Enhanced version for element-specific mass computation.

Parameters

[in]	ielem	Element index for potential state tracking
[in]	ip	Integration point index within the element

Returns

Material mass matrix for the specified location

Reimplemented from Material.

getMaterialMass() [3/4]

void ElasticRodMaterial::getMaterialMass ( const Matrix &  mass ) const

overridevirtual

Default mass matrix in output form.

Parameters

[out]

mass

Material mass matrix, overwritten

Note

Default implementation copies getMaterialMass()

Reimplemented from Material.

getMaterialMass() [4/4]

void ElasticRodMaterial::getMaterialMass ( const Matrix &  mass, const idx_t &  ielem, const idx_t &  ip  ) const

overridevirtual

Default element-specific mass matrix in output form.

Parameters

[out]	mass	Material mass matrix, overwritten
[in]	ielem	Element index
[in]	ip	Integration point index

Note

Default implementation copies getMaterialMass(ielem, ip)

Reimplemented from Material.

getMaterialStiff() [1/4]

Matrix ElasticRodMaterial::getMaterialStiff ( ) const

overridevirtual

Computes the material stiffness matrix relating stress to strain. This matrix represents the tangent modulus of the material at the current state.

Returns

Material stiffness matrix

Implements Material.

getMaterialStiff() [2/4]

Matrix ElasticRodMaterial::getMaterialStiff ( const idx_t &  ielem, const idx_t &  ip  ) const

overridevirtual

Default element-specific stiffness matrix.

Enhanced version that allows state-dependent stiffness computation.

Parameters

[in]	ielem	Element index for state tracking
[in]	ip	Integration point index within the element

Returns

Material stiffness matrix for the specified location

Note

Default implementation delegates to getMaterialStiff()

Reimplemented from Material.

getMaterialStiff() [3/4]

void ElasticRodMaterial::getMaterialStiff ( const Matrix &  stiff ) const

overridevirtual

Default stiffness matrix in output form.

Parameters

[out]

stiff

Material stiffness matrix, overwritten

Note

Default implementation copies getMaterialStiff()

Reimplemented from Material.

getMaterialStiff() [4/4]

void ElasticRodMaterial::getMaterialStiff ( const Matrix &  stiff, const idx_t &  ielem, const idx_t &  ip  ) const

overridevirtual

Default element-specific stiffness matrix in output form.

Parameters

[out]	stiff	Material stiffness matrix, overwritten
[in]	ielem	Element index
[in]	ip	Integration point index

Note

Default implementation copies getMaterialStiff(ielem, ip)

Reimplemented from Material.

getPotentialEnergy()

double ElasticRodMaterial::getPotentialEnergy ( const idx_t &  ielem, const idx_t &  ip  ) const

overridevirtual

Computes the stored elastic energy at the specified element and integration point location.

Parameters

[in]	ielem	Element index
[in]	ip	Integration point index within the element

Returns

Elastic potential energy at the specified location

Note

Contract: must return the value of the last committed state, i.e. it has to be stored in applyDeform(). SpecialCosseratRodModel::getEnergies_ reads it right after applyDeform() without re-evaluating strains/stresses.

0 for purely elastic materials

Implements Material.

Reimplemented in ElastoPlasticRodMaterial.

getStress() [1/2]

void ElasticRodMaterial::getStress ( const Vector &  stress, const Vector &  strain  )

overridevirtual

Fundamental constitutive relationship defining material response to deformation. All derived material classes must implement this method.

Parameters

[out]	stress	Computed stress vector at current state
[in]	strain	Input strain vector for stress computation

Note

For rod elements: 6-dimensional vectors (axial, shear, bending, torsion)

Implements Material.

Reimplemented in ElastoPlasticRodMaterial.

getStress() [2/2]

void ElasticRodMaterial::getStress ( const Vector &  stress, const Vector &  strain, const idx_t &  ielem, const idx_t &  ip, const bool  inelastic = false  )

overridevirtual

Default element-specific stress computation.

Parameters

[out]	stress	Computed stress vector
[in]	strain	Input strain vector
[in]	ielem	Element index for state tracking
[in]	ip	Integration point index
[in]	inelastic	Enable inelastic behavior (default: true)

Note

Default delegates to getStress(stress, strain) ElastoPlasticRodMaterial overrides for plastic state management

Reimplemented from Material.

Reimplemented in ElastoPlasticRodMaterial.

getTable()

void ElasticRodMaterial::getTable ( XTable &  strain_table, const Vector &  weights, const String &  name, const IdxVector &  items  ) const

overridevirtual

This method fills an XTable with strain-related data for output or post-processing purposes. The specific data depends on the material type.

Parameters

[out]	strain_table	Output table to populate with strain data
[in,out]	weights	Weight vector for data averaging or integration
[in]	name	Name identifier for the table data
[in]	items	Index vector specifying which items to include

Implements Material.

Reimplemented in ElastoPlasticRodMaterial.

makeNew()

Ref< Material > ElasticRodMaterial::makeNew ( const String &  name, const Properties &  conf, const Properties &  props, const Properties &  globdat  )

static

Parameters

[in]	name	Material instance name
[out]	conf	Actually used configuration properties
[in]	props	User-specified material properties
[in]	globdat	Global data container

Returns

Reference to the created material

rejectDeform()

void ElasticRodMaterial::rejectDeform ( )

overridevirtual

This method reverts the material to its state before the current load step. It's called when a load step fails to converge or needs to be repeated.

Implements Material.

Reimplemented in ElastoPlasticRodMaterial.

Member Data Documentation

AREA

const char * ElasticRodMaterial::AREA = "area"

static

area_

double ElasticRodMaterial::area_

protected

AREA_MOMENT

const char * ElasticRodMaterial::AREA_MOMENT = "area_moment"

static

areaMoment_

Vector ElasticRodMaterial::areaMoment_

protected

CROSS_SECTION

const char * ElasticRodMaterial::CROSS_SECTION = "cross_section"

static

crossSection_

String ElasticRodMaterial::crossSection_

protected

currStrains_

Cubix ElasticRodMaterial::currStrains_

protected

DENSITY

const char * ElasticRodMaterial::DENSITY = "density"

static

density_

double ElasticRodMaterial::density_

protected

EDGE_ELEMS

const char * ElasticRodMaterial::EDGE_ELEMS = "edge_elements"

static

EDGE_FACTOR

const char * ElasticRodMaterial::EDGE_FACTOR = "edge_factor"

static

edgeElems_

idx_t ElasticRodMaterial::edgeElems_

protected

edgeFact_

double ElasticRodMaterial::edgeFact_

protected

energyPot_

Matrix ElasticRodMaterial::energyPot_

protected

materialK_

Matrix ElasticRodMaterial::materialK_

protected

materialM_

Matrix ElasticRodMaterial::materialM_

protected

matvec_

jem::numeric::MatmulChain<double, 1> ElasticRodMaterial::matvec_

protected

Matrix-vector products without creating new arrays; the result is valid until the next call (see the note in utils/helpers.h)

N_ELEM

const char * ElasticRodMaterial::N_ELEM = "elemCount"

static

nElem_

idx_t ElasticRodMaterial::nElem_

protected

oldStrains_

Cubix ElasticRodMaterial::oldStrains_

protected

POISSON_RATIO

const char * ElasticRodMaterial::POISSON_RATIO = "poisson_ratio"

static

POLAR_MOMENT

const char * ElasticRodMaterial::POLAR_MOMENT = "polar_moment"

static

polarMoment_

double ElasticRodMaterial::polarMoment_

protected

RADIUS

const char * ElasticRodMaterial::RADIUS = "radius"

static

radius_

double ElasticRodMaterial::radius_

protected

rodName_

String ElasticRodMaterial::rodName_

protected

SHEAR_FACTOR

const char * ElasticRodMaterial::SHEAR_FACTOR = "shear_correction"

static

SHEAR_MODULUS

const char * ElasticRodMaterial::SHEAR_MODULUS = "shear_modulus"

static

shearMod_

double ElasticRodMaterial::shearMod_

protected

shearParam_

double ElasticRodMaterial::shearParam_

protected

SIDE_LENGTH

const char * ElasticRodMaterial::SIDE_LENGTH = "side_length"

static

sideLength_

Vector ElasticRodMaterial::sideLength_

protected

STIFF_PREFIX

const char * ElasticRodMaterial::STIFF_PREFIX = "C_"

static

stiffWork_

Matrix ElasticRodMaterial::stiffWork_

protected

TYPE_NAME

const char * ElasticRodMaterial::TYPE_NAME = "ElasticRod"

static

young_

double ElasticRodMaterial::young_

protected

YOUNGS_MODULUS

const char * ElasticRodMaterial::YOUNGS_MODULUS = "young"

static