TriangularFEMForceField

Corotational Triangular finite elements for dynamic topology

Templates:

• Vec3d

Target: Sofa.Component.SolidMechanics.FEM.Elastic

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

parents:

• ForceField

Data:

Name	Description	Default value
name	object name	unnamed
printLog	if true, emits extra messages at runtime.	0
tags	list of the subsets the objet 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
isCompliance	Consider the component as a compliance, else as a stiffness	0
rayleighStiffness	Rayleigh damping - stiffness matrix coefficient	0
triangleInfo	Internal triangle data
vertexInfo	Internal point data
method	large: large displacements, small: small displacements	large
poissonRatio	Poisson ratio in Hooke's law (vector)	0.3
youngModulus	Young modulus in Hooke's law (vector)	1000
rotatedInitialElements	Flag activating rendering of stress directions within each triangle
initialTransformation	Flag activating rendering of stress directions within each triangle
hosfordExponant	Exponant in the Hosford yield criteria	1
criteriaValue	Fracturable threshold used to draw fracturable triangles	1e+15
computePrincipalStress	Compute principal stress for each triangle	0
Visualization
showStressValue	Flag activating rendering of stress values as a color in each triangle	1
showStressVector	Flag activating rendering of stress directions within each triangle	0
showFracturableTriangles	Flag activating rendering of triangles to fracture	0

Links:

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

Examples

Component/SolidMechanics/FEM/TriangularFEMForceFieldOptim.scn

XMLPython

<!-- Mechanical TriangularFEMForceFieldOptim Example -->
<Node name="root" dt="0.05" gravity="0 10 10" showBoundingTree="0">
    <RequiredPlugin name="Sofa.Component.Constraint.Projective"/> <!-- Needed to use components [FixedProjectiveConstraint] -->
    <RequiredPlugin name="Sofa.Component.IO.Mesh"/> <!-- Needed to use components [MeshGmshLoader] -->
    <RequiredPlugin name="Sofa.Component.LinearSolver.Iterative"/> <!-- Needed to use components [CGLinearSolver] -->
    <RequiredPlugin name="Sofa.Component.Mapping.Linear"/> <!-- Needed to use components [IdentityMapping] -->
    <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 [TriangularFEMForceFieldOptim] -->
    <RequiredPlugin name="Sofa.Component.StateContainer"/> <!-- Needed to use components [MechanicalObject] -->
    <RequiredPlugin name="Sofa.Component.Topology.Container.Dynamic"/> <!-- Needed to use components [TriangleSetGeometryAlgorithms TriangleSetTopologyContainer TriangleSetTopologyModifier] -->
    <RequiredPlugin name="Sofa.Component.Visual"/> <!-- Needed to use components [VisualStyle] -->
    <RequiredPlugin name="Sofa.GL.Component.Rendering3D"/> <!-- Needed to use components [OglModel] -->

    <VisualStyle displayFlags="showVisual showBehaviorModels showForceFields showWireframe" />
    <DefaultAnimationLoop/>
    <!-- Activate this loader to use a square mesh with only two triangles (useful to debug base equations) -->
    <!--<MeshGmshLoader name="loaderSquare" triangles="0 1 3  1 2 3" position="0 0 0  1 0 0  1 1 0  0 1 0" />-->
    <!-- Activate this loader to load a square mesh with many triangles -->
    <MeshGmshLoader filename="mesh/square3.msh" name="loaderSquare" />
    <Node name="SquareGravity1">
        <EulerImplicitSolver name="odesolver1" printLog="0"  rayleighStiffness="0.1" rayleighMass="0.1" />
        <CGLinearSolver verbose="0" printLog="0" iterations="25" name="linearsolver1" tolerance="1.0e-9" threshold="1.0e-9" />
        <TriangleSetTopologyContainer name="Container" src="@../loaderSquare" />
        <MechanicalObject name="DOFs" src="@../loaderSquare" scale="100"  />
        <TriangleSetTopologyModifier name="Modifier" />
        <TriangleSetGeometryAlgorithms name="GeomAlgo" template="Vec3" />
        <DiagonalMass massDensity="0.005" />
        <FixedProjectiveConstraint indices="0 1 2" />
        <TriangularFEMForceFieldOptim name="FEM" youngModulus="600" poissonRatio="0.3" method="large" printLog="1"/>
        <Node name="VisuA">
            <OglModel name="Visual" color="yellow" />
            <IdentityMapping name="visualMapping" input="@../DOFs" output="@Visual" />
        </Node>
    </Node>
    <!-- Activate this version to compare computed stiffness matrix (addKToMatrix) with addDForce -->
    <!--<Node name="SquareGravityTestMatrixConstruction">
        <EulerImplicitSolver name="odesolver2" printLog="0" />
        <CGLinearSolver template="SparseMatrix" verbose="0" printLog="1" iterations="25" name="linearsolver2" tolerance="1.0e-9" threshold="1.0e-9" />
        <TriangleSetTopologyContainer name="Container" src="@../loaderSquare" />
        <MechanicalObject name="DOFs" src="@../loaderSquare" scale="100"  />
        <TriangleSetTopologyModifier name="Modifier" />
        <TriangleSetGeometryAlgorithms name="GeomAlgo" template="Vec3" />
        <DiagonalMass massDensity="0.005" />
        <FixedProjectiveConstraint indices="0 1 2" />
        <TriangularFEMForceFieldOptim name="FEM" youngModulus="600" poissonRatio="0.3" method="large" printLog="1"/>
        <Node name="VisuA">
            <OglModel name="Visual" color="yellow" />
            <IdentityMapping name="visualMapping" input="@../DOFs" output="@Visual" />
        </Node>
    </Node>-->

</Node>

def createScene(rootNode):

    root = rootNode.addChild('root', dt="0.05", gravity="0 10 10", showBoundingTree="0")
    root.addObject('RequiredPlugin', name="Sofa.Component.Constraint.Projective")
    root.addObject('RequiredPlugin', name="Sofa.Component.IO.Mesh")
    root.addObject('RequiredPlugin', name="Sofa.Component.LinearSolver.Iterative")
    root.addObject('RequiredPlugin', name="Sofa.Component.Mapping.Linear")
    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.Visual")
    root.addObject('RequiredPlugin', name="Sofa.GL.Component.Rendering3D")
    root.addObject('VisualStyle', displayFlags="showVisual showBehaviorModels showForceFields showWireframe")
    root.addObject('DefaultAnimationLoop')
    root.addObject('MeshGmshLoader', filename="mesh/square3.msh", name="loaderSquare")

    SquareGravity1 = root.addChild('SquareGravity1')
    SquareGravity1.addObject('EulerImplicitSolver', name="odesolver1", printLog="0", rayleighStiffness="0.1", rayleighMass="0.1")
    SquareGravity1.addObject('CGLinearSolver', verbose="0", printLog="0", iterations="25", name="linearsolver1", tolerance="1.0e-9", threshold="1.0e-9")
    SquareGravity1.addObject('TriangleSetTopologyContainer', name="Container", src="@../loaderSquare")
    SquareGravity1.addObject('MechanicalObject', name="DOFs", src="@../loaderSquare", scale="100")
    SquareGravity1.addObject('TriangleSetTopologyModifier', name="Modifier")
    SquareGravity1.addObject('TriangleSetGeometryAlgorithms', name="GeomAlgo", template="Vec3")
    SquareGravity1.addObject('DiagonalMass', massDensity="0.005")
    SquareGravity1.addObject('FixedProjectiveConstraint', indices="0 1 2")
    SquareGravity1.addObject('TriangularFEMForceFieldOptim', name="FEM", youngModulus="600", poissonRatio="0.3", method="large", printLog="1")

    VisuA = SquareGravity1.addChild('VisuA')
    VisuA.addObject('OglModel', name="Visual", color="yellow")
    VisuA.addObject('IdentityMapping', name="visualMapping", input="@../DOFs", output="@Visual")

Component/SolidMechanics/FEM/TriangularFEMForceField.scn

XMLPython

<!-- Mechanical TriangularFEMForceField Example -->
<Node name="root" dt="0.05" gravity="0 -9.8 10" showBoundingTree="0">

    <Node name="plugins">
        <RequiredPlugin name="Sofa.Component.Constraint.Projective"/> <!-- Needed to use components [FixedProjectiveConstraint] -->
        <RequiredPlugin name="Sofa.Component.IO.Mesh"/> <!-- Needed to use components [MeshGmshLoader] -->
        <RequiredPlugin name="Sofa.Component.LinearSolver.Iterative"/> <!-- Needed to use components [CGLinearSolver] -->
        <RequiredPlugin name="Sofa.Component.Mapping.Linear"/> <!-- Needed to use components [IdentityMapping] -->
        <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 [TriangularFEMForceField] -->
        <RequiredPlugin name="Sofa.Component.StateContainer"/> <!-- Needed to use components [MechanicalObject] -->
        <RequiredPlugin name="Sofa.Component.Topology.Container.Dynamic"/> <!-- Needed to use components [TriangleSetGeometryAlgorithms TriangleSetTopologyContainer TriangleSetTopologyModifier] -->
        <RequiredPlugin name="Sofa.Component.Visual"/> <!-- Needed to use components [VisualStyle] -->
        <RequiredPlugin name="Sofa.GL.Component.Rendering3D"/> <!-- Needed to use components [OglModel] -->
    </Node>

    <VisualStyle displayFlags="showBehaviorModels showVisual" />
    <DefaultAnimationLoop/>

    <Node name="SquareGravity">
        <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" />
        <MeshGmshLoader filename="mesh/square3.msh" name="loader" />
        <MechanicalObject src="@loader" name="DOFs" scale3d="100 100 0" />
        <TriangleSetTopologyContainer src="@loader" name="Container" />
        <TriangleSetTopologyModifier name="Modifier" />
        <TriangleSetGeometryAlgorithms name="GeomAlgo" template="Vec3" />
        <DiagonalMass massDensity="0.005" />
        <FixedProjectiveConstraint indices="0 1 2" />
        <TriangularFEMForceField name="FEM" youngModulus="600" poissonRatio="0.3" method="large" />
        <Node name="VisuA">
            <OglModel name="Visual" color="yellow" />
            <IdentityMapping template="Vec3,Vec3" name="visualMapping" input="@../DOFs" output="@Visual" />
        </Node>
    </Node>
</Node>

def createScene(rootNode):

    root = rootNode.addChild('root', dt="0.05", gravity="0 -9.8 10", showBoundingTree="0")

    plugins = root.addChild('plugins')
    plugins.addObject('RequiredPlugin', name="Sofa.Component.Constraint.Projective")
    plugins.addObject('RequiredPlugin', name="Sofa.Component.IO.Mesh")
    plugins.addObject('RequiredPlugin', name="Sofa.Component.LinearSolver.Iterative")
    plugins.addObject('RequiredPlugin', name="Sofa.Component.Mapping.Linear")
    plugins.addObject('RequiredPlugin', name="Sofa.Component.Mass")
    plugins.addObject('RequiredPlugin', name="Sofa.Component.ODESolver.Backward")
    plugins.addObject('RequiredPlugin', name="Sofa.Component.SolidMechanics.FEM.Elastic")
    plugins.addObject('RequiredPlugin', name="Sofa.Component.StateContainer")
    plugins.addObject('RequiredPlugin', name="Sofa.Component.Topology.Container.Dynamic")
    plugins.addObject('RequiredPlugin', name="Sofa.Component.Visual")
    plugins.addObject('RequiredPlugin', name="Sofa.GL.Component.Rendering3D")
    root.addObject('VisualStyle', displayFlags="showBehaviorModels showVisual")
    root.addObject('DefaultAnimationLoop')

    SquareGravity = root.addChild('SquareGravity')
    SquareGravity.addObject('EulerImplicitSolver', name="cg_odesolver", printLog="false", rayleighStiffness="0.1", rayleighMass="0.1")
    SquareGravity.addObject('CGLinearSolver', iterations="25", name="linear solver", tolerance="1.0e-9", threshold="1.0e-9")
    SquareGravity.addObject('MeshGmshLoader', filename="mesh/square3.msh", name="loader")
    SquareGravity.addObject('MechanicalObject', src="@loader", name="DOFs", scale3d="100 100 0")
    SquareGravity.addObject('TriangleSetTopologyContainer', src="@loader", name="Container")
    SquareGravity.addObject('TriangleSetTopologyModifier', name="Modifier")
    SquareGravity.addObject('TriangleSetGeometryAlgorithms', name="GeomAlgo", template="Vec3")
    SquareGravity.addObject('DiagonalMass', massDensity="0.005")
    SquareGravity.addObject('FixedProjectiveConstraint', indices="0 1 2")
    SquareGravity.addObject('TriangularFEMForceField', name="FEM", youngModulus="600", poissonRatio="0.3", method="large")

    VisuA = SquareGravity.addChild('VisuA')
    VisuA.addObject('OglModel', name="Visual", color="yellow")
    VisuA.addObject('IdentityMapping', template="Vec3,Vec3", name="visualMapping", input="@../DOFs", output="@Visual")

Benchmark/TopologicalChanges/TriangularFEMForceField_RemovingMeshTest.scn

XMLPython

<?xml version="1.0" ?>
<!-- Automatic Triangle removal on a simple Triangle topology with FEM: Element removed are define in: ./RemovingTrianglesProcess.txt -->
<Node name="root" gravity="0 -9 0" dt="0.01"  bbox="-1 -1 -1 1 1 1">
    <RequiredPlugin name="Sofa.Component.Collision.Detection.Algorithm"/> <!-- Needed to use components [BVHNarrowPhase BruteForceBroadPhase CollisionPipeline] -->
    <RequiredPlugin name="Sofa.Component.Collision.Detection.Intersection"/> <!-- Needed to use components [MinProximityIntersection] -->
    <RequiredPlugin name="Sofa.Component.Collision.Response.Contact"/> <!-- Needed to use components [CollisionResponse] -->
    <RequiredPlugin name="Sofa.Component.IO.Mesh"/> <!-- Needed to use components [MeshGmshLoader] -->
    <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 [TriangularFEMForceField] -->
    <RequiredPlugin name="Sofa.Component.StateContainer"/> <!-- Needed to use components [MechanicalObject] -->
    <RequiredPlugin name="Sofa.Component.Topology.Container.Dynamic"/> <!-- Needed to use components [TriangleSetGeometryAlgorithms TriangleSetTopologyContainer TriangleSetTopologyModifier] -->
    <RequiredPlugin name="Sofa.Component.Topology.Utility"/> <!-- Needed to use components [TopologicalChangeProcessor] -->
    <RequiredPlugin name="Sofa.Component.Visual"/> <!-- Needed to use components [VisualStyle] -->

    <VisualStyle displayFlags="showVisual showBehaviorModels showForceFields" />
    <DefaultAnimationLoop/>
    <CollisionPipeline verbose="0" />
    <BruteForceBroadPhase name="N2" />
    <BVHNarrowPhase />
    <CollisionResponse response="PenalityContactForceField" />
    <MinProximityIntersection name="Proximity" alarmDistance="0.8" contactDistance="0.5" />
    <Node name="SquareGravity">
        <EulerImplicitSolver name="cg_odesolver" rayleighStiffness="0.1" rayleighMass="0.1" />
        <CGLinearSolver iterations="25" tolerance="1e-5" threshold="1e-5" name="linear solver"/>
        <MeshGmshLoader name="loader" filename="mesh/square3.msh" createSubelements="true" />
        <MechanicalObject name="dofs" src="@loader" template="Vec3" />
        <TriangleSetTopologyContainer name="Triangle_topo" src="@loader"/>
        <TriangleSetTopologyModifier name="Modifier" />
        <TriangleSetGeometryAlgorithms template="Vec3" name="GeomAlgo" />
        <DiagonalMass template="Vec3,Vec3" name="mass" massDensity="1.0" />

        <TriangularFEMForceField template="Vec3" name="FEM" method="large" poissonRatio="0.3" youngModulus="60" />

        <TopologicalChangeProcessor listening="1" filename="RemovingTrianglesProcess_constraint.txt" />
    </Node>
</Node>

def createScene(rootNode):

    root = rootNode.addChild('root', gravity="0 -9 0", dt="0.01", bbox="-1 -1 -1 1 1 1")
    root.addObject('RequiredPlugin', name="Sofa.Component.Collision.Detection.Algorithm")
    root.addObject('RequiredPlugin', name="Sofa.Component.Collision.Detection.Intersection")
    root.addObject('RequiredPlugin', name="Sofa.Component.Collision.Response.Contact")
    root.addObject('RequiredPlugin', name="Sofa.Component.IO.Mesh")
    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.Utility")
    root.addObject('RequiredPlugin', name="Sofa.Component.Visual")
    root.addObject('VisualStyle', displayFlags="showVisual showBehaviorModels showForceFields")
    root.addObject('DefaultAnimationLoop')
    root.addObject('CollisionPipeline', verbose="0")
    root.addObject('BruteForceBroadPhase', name="N2")
    root.addObject('BVHNarrowPhase')
    root.addObject('CollisionResponse', response="PenalityContactForceField")
    root.addObject('MinProximityIntersection', name="Proximity", alarmDistance="0.8", contactDistance="0.5")

    SquareGravity = root.addChild('SquareGravity')
    SquareGravity.addObject('EulerImplicitSolver', name="cg_odesolver", rayleighStiffness="0.1", rayleighMass="0.1")
    SquareGravity.addObject('CGLinearSolver', iterations="25", tolerance="1e-5", threshold="1e-5", name="linear solver")
    SquareGravity.addObject('MeshGmshLoader', name="loader", filename="mesh/square3.msh", createSubelements="true")
    SquareGravity.addObject('MechanicalObject', name="dofs", src="@loader", template="Vec3")
    SquareGravity.addObject('TriangleSetTopologyContainer', name="Triangle_topo", src="@loader")
    SquareGravity.addObject('TriangleSetTopologyModifier', name="Modifier")
    SquareGravity.addObject('TriangleSetGeometryAlgorithms', template="Vec3", name="GeomAlgo")
    SquareGravity.addObject('DiagonalMass', template="Vec3,Vec3", name="mass", massDensity="1.0")
    SquareGravity.addObject('TriangularFEMForceField', template="Vec3", name="FEM", method="large", poissonRatio="0.3", youngModulus="60")
    SquareGravity.addObject('TopologicalChangeProcessor', listening="1", filename="RemovingTrianglesProcess_constraint.txt")