ConstitutiveLaws

From Yade

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.

Please add what you know something about.

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 articles) e.g. Scholtes2009c triax-basic.py Bruno Chareyre
Law2_CylScGeom6D_CohFrictPhys_CohesionMoment
Law2_CylScGeom_FrictPhys_CundallStrack
Law2_Dem3DofGeom_CpmPhys_Cpm
Law2_Dem3DofGeom_RockPMPhys_Rpm
Law2_L3Geom_FrictPhys_ElPerfPl
Law2_L6Geom_FrictPhys_Linear
Law2_ScGeom6D_CohFrictPhys_CohesionMoment
Law2_ScGeom6D_NormalInelasticityPhys_NormalInelasticity
Law2_ScGeom_CFpmPhys_CohesiveFrictionalPM
Law2_ScGeom_CpmPhys_Cpm
Law2_ScGeom_FrictPhys_CundallStrack
Law2_ScGeom_MindlinPhys_HertzWithLinearShear
Law2_ScGeom_MindlinPhys_Mindlin
Law2_ScGeom_MindlinPhys_MindlinDeresiewitz
Law2_ScGeom_ViscElPhys_Basic
Law2_ScGeom_ViscoFrictPhys_CundallStrack
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_SomeGeom_CpmPhys_Cpm
A less stable law
Experimental, unmaintained, or even broken law

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).