ConstitutiveLaws

This page should grow to give overview of all constitutive laws in Yade. The purpose is twofold:

1. Names of respective classes do not say much and it seems that lot of code is duplicated; should improve orientation in material models available
2. Not all laws are in the same development stage. Some of them are well validated while others are purely experimental. Users should quickly find out which ones are safe to use in this table.

Yade users are strongly encouraged to choose one of the green laws unless a reason exist to decide otherwise.

Constitutive laws

Class	description	dev. status	validated	publications	example script	maintainer(s)
Law2_ScGeom_FrictPhys_CundallStrack	The traditional Cundall's linear elastic-plastic law. This law has three parameters : tangential stiffness, normal stiffness, and friction coefficient - it modelizes dry contacts (no tensile force allowed).	mature	yes	(>10 papers) e.g. Scholtes2009c, Chareyre2012a	triax-basic.py	Bruno Chareyre
Law2_ScGeom6D_CohFrictPhys_CohesionMoment	An augmented version of Law2_ScGeom_FrictPhys_CundallStrack with cohesion and torques at contacts. Creep is optional.	mature	yes	not yet	triax-cohesive.py	Bruno Chareyre
Law2_ScGeom_MindlinPhys_Mindlin	The non-linear elastic Hertz-Mindlin no-slip solution contact law. The law also allows for rolling resistance and non-linear viscous damping.	mature	yes	Modenese2012b	mindlin.py	Chiara Modenese
Law2_ScGeom_WirePhys_WirePM	A contact law for steel wires which is defined by a piece-wise linear stress-strain curve. The contact law considers tensile forces only.	mature	yes	Thoeni2011, Bertrand2008	WireMatPM/wirecontacttest.py WireMatPM/wiretensiltest.py	Klaus Thoeni
Law2_CylScGeom_FrictPhys_CundallStrack	Similar to Law2_ScGeom_FrictPhys_CundallStrack but adapted to interactions between spheres and chained cylinders.	in development	more or less	not yet	chained-cylinder-roots.py	Bruno Chareyre, François Kneib
Law2_CylScGeom6D_CohFrictPhys_CohesionMoment	Similar to Law2_ScGeom6D_CohFrictPhys_CohesionMoment but adapted to interactions between spheres and chained cylinders.	in development	no	not yet	CohesiveCylinderSphere.py	François Kneib, Bruno Chareyre
Law2_ScGeom_ViscoFrictPhys_CundallStrack	Generalized Maxwell model of visco-elasto-plastic interactions (2 springs and 2 dashpots for each force component).	in development	no		-	Bruno Chareyre
Law2_SomeGeom_CpmPhys_Cpm	A generic class for inheritance by more specialized functors (e.g.Law2_ScGeom_CpmPhys_Cpm). Not to be used in simulations.
Law2_Dem3DofGeom_CpmPhys_Cpm
Law2_Dem3DofGeom_RockPMPhys_Rpm
Law2_L3Geom_FrictPhys_ElPerfPl
Law2_L6Geom_FrictPhys_Linear
Law2_ScGeom6D_NormalInelasticityPhys_NormalInelasticity
Law2_ScGeom_CFpmPhys_CohesiveFrictionalPM
Law2_ScGeom_CpmPhys_Cpm
Law2_ScGeom_MindlinPhys_HertzWithLinearShear
Law2_ScGeom_MindlinPhys_MindlinDeresiewitz
Law2_ScGeom_ViscElPhys_Basic

Older tables (removed soon)

Class	description	interactionGeometry	interactionPhysics	used by and where
ElasticContactLaw	(the traditional Cundall's elastic-plastic law) This law has three parameters : tangential stiffness, normal stiffness, and friction coefficient - it modelises dry contacts (no tensile force allowed).	SpheresContactGeometry	ElasticContactInteraction	TriaxialTest (Bruno Chareyre)
CohesiveFrictionalContactLaw	A versatile elastic-plastic contact law, with shear/normal/twisting/rolling stiffnesses, normal/shear strength (twisting/rolling strength could be added easily, for now they are infinite), shear/twisting creep	SpheresContactGeometry	CohesiveFrictionalInteraction	CohesiveTriaxialTest (Bruno Chareyre/Cosurgi)
Concrete particle model (Cpm)	material model developed for concrete. It has damage, plasticity (friction), visco-damage (and visco-plasticity). The code unfortunately cannot be disclosed by contract, but algorithms will be published some day.	Dem3DofGeom	CpmPhys	scripts (eudoxos)
ef2_Spheres_NormalShear_ElasticFrictionalLaw	Proof-of-concept for ConstitutiveLawDispatcher. Cohesive type of interaction; has elasticity in both normal and shear directions.	SpheresContactGeometry	NormalShearInteraction	scripts/constitutive-law.py (eudoxos)
ElasticContactLaw2	like ElasticContactLaw, but using geometry algorithms in SpheresContactGeometry instead of computing that in-place; demonstrative only	SpheresContactGeometry	ElasticContactInteraction	(eudoxos)
ElasticCohesiveLaw (deprecated)	inherited from SDEC, not used anywhere except SDECLinkedSpheres	SDECLinkGeometry	SDECLinkPhysics	to be removed (relies on persistentInteractions)?
Spheres_Viscoelastic_SimpleViscoelasticContactLaw	Linear spring−dashpot contact model	SpheresContactGeometry	ViscoelasticInteraction	(sega) for dynamic simulation
RockJointLaw	Inelastic normal behaviour (kn_unload # kn_load); transfert of an elastic-plastic moment; no cohesion or tensile limit	SpheresContactGeometry	RockJointPhys	J. Duriez for simulations of "SimpleShear" Preprocessor (a simple shear box for studying rock joints)
Law2_ScGeom_CapillaryPhys_Capillarity	This law allows to take into account capillary forces/effects between spheres coming from the presence of interparticular liquid bridges (menisci). The law needs ascii files M(r=i) to work (see https://yade-dem.org/index.php/CapillaryTriaxialTest). These ASCII files contain a set of results from the resolution of the Laplace-Young equation for different configurations of the interacting geometry.	SpheresContactGeometry	CapillaryPhys	L. Scholtes for simulation of unsaturated granular materials (e.g. TriaxialTestWater)
add your stuff here, please!	...	...	...

InteractionPhysicsFunctors

Class	description	material	interactionPhysics	remarks
Ip2_CpmMat_CpmMat_CpmPhys	from the Cpm family; elastic, damage, plasticity, viscosity properties	CpmMat	CpmPhys	(eudoxos)
SimpleElasticRelationships	...	...	...
SimpleViscoelasticRelationships	From viscoelastic parameters of the pair bodies provides viscoelastic parameters of their interaction by the rule of consecutive connection.	SimpleViscoelasticBodyParameters	ViscoelasticInteraction	(sega)
RockJointLawRelationships	Computes all the attributes of "RockJointPhys" used for application of RockJointLaw	CohesiveFrictionalBodyParameters	RockJointPhys	J. Duriez for SimpleShear
Ip2_FrictMat_FrictMat_CapillaryPhys	computes all the elastic attributes for CapillaryPhys (duplicates Ip2_FrictMat_FrictMat_FrictPhys)	Frictmat	CapillaryPhys	Luc Scholtes

InteractionGeometry

Class	description
SpheresContactGeometry	used almost everywhere in the DEM code, even for sphere-box contacts.
SDECLinkGeometry	duplicated SpheresContactGeometry. (Should be removed)
...	.....

InteractionPhysics

Class	description
NormalInteraction	abstract class that has only normal stiffness and force
NormalShearInteraction	abstract class with normal and shear stiffnesses
CpmPhys	normal and shear physics with additional parameters for non-elastic domain.
ViscoelasticInteraction	elastic contact with additional parameters for normal and shear dashpot.
RockJointPhys
CapillaryPhys	parameters linked to the definition of a capillary bridge between 2 spheres (Volume,Force,extents over grains surfaces).