TetrahedralCorotationalFEMForceField

Corotational FEM Tetrahedral finite elements

Vec3d

Templates:

• Vec3d

Target: Sofa.Component.SolidMechanics.FEM.Elastic

namespace: sofa::component::solidmechanics::fem::elastic

parents:

• BaseLinearElasticityFEMForceField

Data

Name	Description	Default value
name	object name	unnamed
printLog	if true, emits extra messages at runtime.	0
tags	list of the subsets the object belongs to
bbox	this object bounding box
componentState	The state of the component among (Dirty, Valid, Undefined, Loading, Invalid).	Undefined
listening	if true, handle the events, otherwise ignore the events	0
rayleighStiffness	Rayleigh damping - stiffness matrix coefficient	0
poissonRatio	FEM Poisson Ratio in Hooke's law [0,0.5[	0.45
youngModulus	FEM Young's Modulus in Hooke's law	5000
tetrahedronInfo	Internal tetrahedron data
method	"small", "large" (by QR) or "polar" displacements	large
localStiffnessFactor	Allow specification of different stiffness per element. If there are N element and M values are specified, the youngModulus factor for element i would be localStiffnessFactor[i*M/N]
updateStiffnessMatrix		0
computeGlobalMatrix		0
computeVonMisesStress	compute and display von Mises stress: 0: no computations, 1: using corotational strain, 2: using full Green strain. Set listening=1	0
vonMisesPerElement	von Mises Stress per element
vonMisesPerNode	von Mises Stress per node
Visualization
drawing	draw the forcefield if true	1
drawColor1	draw color for faces 1	0 0 1 1
drawColor2	draw color for faces 2	0 0.5 1 1
drawColor3	draw color for faces 3	0 1 1 1
drawColor4	draw color for faces 4	0.5 1 1 1

Links

Name	Description	Destination type name
context	Graph Node containing this object (or BaseContext::getDefault() if no graph is used)	BaseContext
slaves	Sub-objects used internally by this object	BaseObject
master	nullptr for regular objects, or master object for which this object is one sub-objects	BaseObject
mechanicalStates	List of mechanical states to which this component is associated	BaseMechanicalState
mstate	MechanicalState used by this component	MechanicalState<Vec3d>
topology	link to the topology container	BaseMeshTopology

Examples

TetrahedralCorotationalFEMForceField.scn

XMLPython

<?xml version="1.0" ?>
<!-- Mechanical Tetrahedral Corotational FEM Basic Example -->
<Node name="root" dt="0.05" showBoundingTree="0" gravity="0 -9 0">
    <RequiredPlugin name="Sofa.Component.Constraint.Projective"/> <!-- Needed to use components [FixedProjectiveConstraint] -->
    <RequiredPlugin name="Sofa.Component.Engine.Select"/> <!-- Needed to use components [BoxROI] -->
    <RequiredPlugin name="Sofa.Component.LinearSolver.Iterative"/> <!-- Needed to use components [CGLinearSolver] -->
    <RequiredPlugin name="Sofa.Component.Mass"/> <!-- Needed to use components [DiagonalMass] -->
    <RequiredPlugin name="Sofa.Component.ODESolver.Backward"/> <!-- Needed to use components [EulerImplicitSolver] -->
    <RequiredPlugin name="Sofa.Component.SolidMechanics.FEM.Elastic"/> <!-- Needed to use components [TetrahedralCorotationalFEMForceField] -->
    <RequiredPlugin name="Sofa.Component.StateContainer"/> <!-- Needed to use components [MechanicalObject] -->
    <RequiredPlugin name="Sofa.Component.Topology.Container.Dynamic"/> <!-- Needed to use components [TetrahedronSetGeometryAlgorithms TetrahedronSetTopologyContainer TetrahedronSetTopologyModifier] -->
    <RequiredPlugin name="Sofa.Component.Topology.Container.Grid"/> <!-- Needed to use components [RegularGridTopology] -->
    <RequiredPlugin name="Sofa.Component.Topology.Mapping"/> <!-- Needed to use components [Hexa2TetraTopologicalMapping] -->
    <RequiredPlugin name="Sofa.Component.Visual"/> <!-- Needed to use components [VisualStyle] -->

    <VisualStyle displayFlags="showBehaviorModels showForceFields" />
    <DefaultAnimationLoop parallelODESolving="true"/>

    <Node name="BeamFEM_SMALL">
        <EulerImplicitSolver name="cg_odesolver" printLog="false"  rayleighStiffness="0.1" rayleighMass="0.1" />
        <CGLinearSolver iterations="25" name="linear solver" tolerance="1.0e-9" threshold="1.0e-9" />

        <RegularGridTopology name="grid" min="-5 -5 0" max="5 5 40" n="5 5 20"/>
        <MechanicalObject template="Vec3" />

        <TetrahedronSetTopologyContainer name="Tetra_topo"/>
        <TetrahedronSetTopologyModifier name="Modifier" />
        <TetrahedronSetGeometryAlgorithms template="Vec3" name="GeomAlgo" />
        <Hexa2TetraTopologicalMapping input="@grid" output="@Tetra_topo" />

        <DiagonalMass massDensity="0.2" />
        <TetrahedralCorotationalFEMForceField name="CFEM" youngModulus="1000" poissonRatio="0.3" method="small" />

        <BoxROI template="Vec3" name="box_roi" box="-6 -6 -1 30 6 0.1" drawBoxes="1" />
        <FixedProjectiveConstraint template="Vec3" indices="@box_roi.indices" />
    </Node>

    <Node name="BeamFEM_LARGE">
        <EulerImplicitSolver name="cg_odesolver" printLog="false"  rayleighStiffness="0.1" rayleighMass="0.1" />
        <CGLinearSolver iterations="25" name="linear solver" tolerance="1.0e-9" threshold="1.0e-9" />

        <RegularGridTopology name="grid" min="-5 -5 0" max="5 5 40" n="5 5 20"/>
        <MechanicalObject template="Vec3" translation="11 0 0"/>

        <TetrahedronSetTopologyContainer name="Tetra_topo" />
        <TetrahedronSetTopologyModifier name="Modifier" />
        <TetrahedronSetGeometryAlgorithms template="Vec3" name="GeomAlgo" />
        <Hexa2TetraTopologicalMapping input="@grid" output="@Tetra_topo" />

        <DiagonalMass massDensity="0.2" />
        <TetrahedralCorotationalFEMForceField name="CFEM" youngModulus="1000" poissonRatio="0.3" method="large" computeVonMisesStress="1"/>

        <BoxROI template="Vec3" name="box_roi" box="-6 -6 -1 30 6 0.1" drawBoxes="1" />
        <FixedProjectiveConstraint template="Vec3" indices="@box_roi.indices" />
    </Node>

    <Node name="BeamFEM_POLAR">
        <EulerImplicitSolver name="cg_odesolver" printLog="false"  rayleighStiffness="0.1" rayleighMass="0.1" />
        <CGLinearSolver iterations="25" name="linear solver" tolerance="1.0e-9" threshold="1.0e-9" />

        <RegularGridTopology name="grid" min="-5 -5 0" max="5 5 40" n="5 5 20"/>
        <MechanicalObject template="Vec3" translation="22 0 0"/>

        <TetrahedronSetTopologyContainer name="Tetra_topo"/>
        <TetrahedronSetTopologyModifier name="Modifier" />
        <TetrahedronSetGeometryAlgorithms template="Vec3" name="GeomAlgo" />
        <Hexa2TetraTopologicalMapping input="@grid" output="@Tetra_topo" />

        <DiagonalMass massDensity="0.2" />
        <TetrahedralCorotationalFEMForceField name="CFEM" youngModulus="1000" poissonRatio="0.3" method="polar" computeVonMisesStress="1"/>

        <BoxROI template="Vec3" name="box_roi" box="-6 -6 -1 30 6 0.1" drawBoxes="1" />
        <FixedProjectiveConstraint template="Vec3" indices="@box_roi.indices" />
    </Node>


</Node>

def createScene(root_node):

   root = root_node.addChild('root', dt="0.05", showBoundingTree="0", gravity="0 -9 0")

   root.addObject('RequiredPlugin', name="Sofa.Component.Constraint.Projective")
   root.addObject('RequiredPlugin', name="Sofa.Component.Engine.Select")
   root.addObject('RequiredPlugin', name="Sofa.Component.LinearSolver.Iterative")
   root.addObject('RequiredPlugin', name="Sofa.Component.Mass")
   root.addObject('RequiredPlugin', name="Sofa.Component.ODESolver.Backward")
   root.addObject('RequiredPlugin', name="Sofa.Component.SolidMechanics.FEM.Elastic")
   root.addObject('RequiredPlugin', name="Sofa.Component.StateContainer")
   root.addObject('RequiredPlugin', name="Sofa.Component.Topology.Container.Dynamic")
   root.addObject('RequiredPlugin', name="Sofa.Component.Topology.Container.Grid")
   root.addObject('RequiredPlugin', name="Sofa.Component.Topology.Mapping")
   root.addObject('RequiredPlugin', name="Sofa.Component.Visual")
   root.addObject('VisualStyle', displayFlags="showBehaviorModels showForceFields")
   root.addObject('DefaultAnimationLoop', parallelODESolving="true")

   beam_fem__small = root.addChild('BeamFEM_SMALL')

   beam_fem__small.addObject('EulerImplicitSolver', name="cg_odesolver", printLog="false", rayleighStiffness="0.1", rayleighMass="0.1")
   beam_fem__small.addObject('CGLinearSolver', iterations="25", name="linear solver", tolerance="1.0e-9", threshold="1.0e-9")
   beam_fem__small.addObject('RegularGridTopology', name="grid", min="-5 -5 0", max="5 5 40", n="5 5 20")
   beam_fem__small.addObject('MechanicalObject', template="Vec3")
   beam_fem__small.addObject('TetrahedronSetTopologyContainer', name="Tetra_topo")
   beam_fem__small.addObject('TetrahedronSetTopologyModifier', name="Modifier")
   beam_fem__small.addObject('TetrahedronSetGeometryAlgorithms', template="Vec3", name="GeomAlgo")
   beam_fem__small.addObject('Hexa2TetraTopologicalMapping', input="@grid", output="@Tetra_topo")
   beam_fem__small.addObject('DiagonalMass', massDensity="0.2")
   beam_fem__small.addObject('TetrahedralCorotationalFEMForceField', name="CFEM", youngModulus="1000", poissonRatio="0.3", method="small")
   beam_fem__small.addObject('BoxROI', template="Vec3", name="box_roi", box="-6 -6 -1 30 6 0.1", drawBoxes="1")
   beam_fem__small.addObject('FixedProjectiveConstraint', template="Vec3", indices="@box_roi.indices")

   beam_fem__large = root.addChild('BeamFEM_LARGE')

   beam_fem__large.addObject('EulerImplicitSolver', name="cg_odesolver", printLog="false", rayleighStiffness="0.1", rayleighMass="0.1")
   beam_fem__large.addObject('CGLinearSolver', iterations="25", name="linear solver", tolerance="1.0e-9", threshold="1.0e-9")
   beam_fem__large.addObject('RegularGridTopology', name="grid", min="-5 -5 0", max="5 5 40", n="5 5 20")
   beam_fem__large.addObject('MechanicalObject', template="Vec3", translation="11 0 0")
   beam_fem__large.addObject('TetrahedronSetTopologyContainer', name="Tetra_topo")
   beam_fem__large.addObject('TetrahedronSetTopologyModifier', name="Modifier")
   beam_fem__large.addObject('TetrahedronSetGeometryAlgorithms', template="Vec3", name="GeomAlgo")
   beam_fem__large.addObject('Hexa2TetraTopologicalMapping', input="@grid", output="@Tetra_topo")
   beam_fem__large.addObject('DiagonalMass', massDensity="0.2")
   beam_fem__large.addObject('TetrahedralCorotationalFEMForceField', name="CFEM", youngModulus="1000", poissonRatio="0.3", method="large", computeVonMisesStress="1")
   beam_fem__large.addObject('BoxROI', template="Vec3", name="box_roi", box="-6 -6 -1 30 6 0.1", drawBoxes="1")
   beam_fem__large.addObject('FixedProjectiveConstraint', template="Vec3", indices="@box_roi.indices")

   beam_fem__polar = root.addChild('BeamFEM_POLAR')

   beam_fem__polar.addObject('EulerImplicitSolver', name="cg_odesolver", printLog="false", rayleighStiffness="0.1", rayleighMass="0.1")
   beam_fem__polar.addObject('CGLinearSolver', iterations="25", name="linear solver", tolerance="1.0e-9", threshold="1.0e-9")
   beam_fem__polar.addObject('RegularGridTopology', name="grid", min="-5 -5 0", max="5 5 40", n="5 5 20")
   beam_fem__polar.addObject('MechanicalObject', template="Vec3", translation="22 0 0")
   beam_fem__polar.addObject('TetrahedronSetTopologyContainer', name="Tetra_topo")
   beam_fem__polar.addObject('TetrahedronSetTopologyModifier', name="Modifier")
   beam_fem__polar.addObject('TetrahedronSetGeometryAlgorithms', template="Vec3", name="GeomAlgo")
   beam_fem__polar.addObject('Hexa2TetraTopologicalMapping', input="@grid", output="@Tetra_topo")
   beam_fem__polar.addObject('DiagonalMass', massDensity="0.2")
   beam_fem__polar.addObject('TetrahedralCorotationalFEMForceField', name="CFEM", youngModulus="1000", poissonRatio="0.3", method="polar", computeVonMisesStress="1")
   beam_fem__polar.addObject('BoxROI', template="Vec3", name="box_roi", box="-6 -6 -1 30 6 0.1", drawBoxes="1")
   beam_fem__polar.addObject('FixedProjectiveConstraint', template="Vec3", indices="@box_roi.indices")