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NewmarkIntegrationScheme

Time integrator using Newmark-beta implicit scheme.

Target: Sofa.Component.IntegrationScheme.Backward

namespace: sofa::component::integrationscheme::backward

parents:

  • AccelerationBasedImplicitIntegrationScheme

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 coefficient related to stiffness, > 0 0
rayleighMass Rayleigh damping coefficient related to mass, > 0 0
beta Factor controlling the 'implicitness' of the position computation with respect to the acceleration. 0.0 means explicit central difference, 1.0/0.6 means linear accelerations scheme 0.25
gamma Factor controlling the 'implicitness' of the velocity computation with respect to the acceleration. To insure unconditional stability, gamma must belong to [2*beta, 1/2]. 0.5
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 BaseComponent
master nullptr for regular objects, or master object for which this object is one sub-objects BaseComponent
linearSolver Linear solver used by this component LinearSolver

Examples

NewmarkIntegrationScheme.scn

<Node name="root" gravity="-1.8 0 100" dt="0.02">
    <RequiredPlugin pluginName="Sofa.Component.Constraint.Projective"/> <!-- Needed to use components [FixedProjectiveConstraint] -->
    <RequiredPlugin pluginName="Sofa.Component.IO.Mesh"/> <!-- Needed to use components [MeshGmshLoader MeshOBJLoader] -->
    <RequiredPlugin pluginName="Sofa.Component.LinearSolver.Direct"/> <!-- Needed to use components [SparseLDLSolver] -->
    <RequiredPlugin pluginName="Sofa.Component.LinearSolver.Iterative"/> <!-- Needed to use components [CGLinearSolver] -->
    <RequiredPlugin pluginName="Sofa.Component.Mapping.Linear"/> <!-- Needed to use components [BarycentricMapping] -->
    <RequiredPlugin pluginName="Sofa.Component.Mass"/> <!-- Needed to use components [UniformMass] -->
    <RequiredPlugin pluginName="Sofa.Component.IntegrationScheme.Backward"/> <!-- Needed to use components [NewmarkIntegrationScheme] -->
    <RequiredPlugin pluginName="Sofa.Component.SolidMechanics.FEM.Elastic"/> <!-- Needed to use components [TetrahedronFEMForceField] -->
    <RequiredPlugin pluginName="Sofa.Component.SolidMechanics.Spring"/> <!-- Needed to use components [MeshSpringForceField] -->
    <RequiredPlugin pluginName="Sofa.Component.StateContainer"/> <!-- Needed to use components [MechanicalObject] -->
    <RequiredPlugin pluginName="Sofa.Component.Topology.Container.Constant"/> <!-- Needed to use components [MeshTopology] -->
    <RequiredPlugin pluginName="Sofa.GL.Component.Rendering3D"/> <!-- Needed to use components [OglModel] -->
    <DefaultAnimationLoop/>

    <Node name="Reference">
        <MeshOBJLoader name="meshLoader_0" filename="mesh/truthcylinder1-bent.obj" scale="0.95" handleSeams="1" />
        <OglModel src="@meshLoader_0" dx="0" dy="-1" dz="0" color="green" />
    </Node>
    <Node name="Springs">
        <NewmarkIntegrationScheme rayleighMass="0" rayleighStiffness="0.1" />
        <SparseLDLSolver/>
        <MeshGmshLoader name="loader" filename="mesh/truthcylinder1.msh" />
        <MeshTopology src="@loader" />
        <MechanicalObject src="@loader" dx="15" />
        <UniformMass totalMass="15" />
        <FixedProjectiveConstraint indices="0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 268 269 270 271 343 345" />
        <MeshSpringForceField name="Spring" tetrasStiffness="1870" tetrasDamping="0" />

        <Node>
            <MeshOBJLoader name="meshLoader_3" filename="mesh/truthcylinder1.obj" handleSeams="1" />
            <OglModel name="Visual" src="@meshLoader_3" color="yellow" dx="15" />
            <BarycentricMapping input="@.." output="@Visual" />
        </Node>
    </Node>

    <Node name="CoFEM">
        <NewmarkIntegrationScheme rayleighMass="0" rayleighStiffness="0.1" />
        <CGLinearSolver iterations="100" tolerance="1e-5" threshold="1e-5"/>
        <MeshGmshLoader name="loader" filename="mesh/truthcylinder1.msh"/>
        <MeshTopology src="@loader" />
        <MechanicalObject src="@loader" dx="30" />
        <UniformMass totalMass="15" />
        <FixedProjectiveConstraint indices="0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 268 269 270 271 343 345" />
        <TetrahedronFEMForceField name="FEM" youngModulus="1116" poissonRatio="0.49" method="polar" />

        <Node>
            <MeshOBJLoader name="meshLoader_2" filename="mesh/truthcylinder1.obj" handleSeams="1" />
            <OglModel name="Visual" src="@meshLoader_2" color="cyan" dx="30" />
            <BarycentricMapping input="@.." output="@Visual" />
        </Node>
    </Node>
    <Node name="LinearFEM">
        <NewmarkIntegrationScheme rayleighMass="0" rayleighStiffness="0.1" />
        <CGLinearSolver iterations="100" tolerance="1e-5" threshold="1e-5"/>
        <MeshGmshLoader name="loader" filename="mesh/truthcylinder1.msh"/>
        <MeshTopology src="@loader" />
        <MechanicalObject src="@loader" dx="45" />
        <UniformMass totalMass="15" />
        <FixedProjectiveConstraint indices="0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 268 269 270 271 343 345" />
        <TetrahedronFEMForceField name="FEM" youngModulus="1116" poissonRatio="0.49" method="small" />

        <Node>
            <MeshOBJLoader name="meshLoader_1" filename="mesh/truthcylinder1.obj" handleSeams="1" />
            <OglModel name="Visual" src="@meshLoader_1" color="red" dx="45" />
            <BarycentricMapping input="@.." output="@Visual" />
        </Node>
    </Node>
</Node>
def createScene(root_node):

   root = root_node.addChild('root', gravity="-1.8 0 100", dt="0.02")

   root.addObject('RequiredPlugin', pluginName="Sofa.Component.Constraint.Projective")
   root.addObject('RequiredPlugin', pluginName="Sofa.Component.IO.Mesh")
   root.addObject('RequiredPlugin', pluginName="Sofa.Component.LinearSolver.Direct")
   root.addObject('RequiredPlugin', pluginName="Sofa.Component.LinearSolver.Iterative")
   root.addObject('RequiredPlugin', pluginName="Sofa.Component.Mapping.Linear")
   root.addObject('RequiredPlugin', pluginName="Sofa.Component.Mass")
   root.addObject('RequiredPlugin', pluginName="Sofa.Component.IntegrationScheme.Backward")
   root.addObject('RequiredPlugin', pluginName="Sofa.Component.SolidMechanics.FEM.Elastic")
   root.addObject('RequiredPlugin', pluginName="Sofa.Component.SolidMechanics.Spring")
   root.addObject('RequiredPlugin', pluginName="Sofa.Component.StateContainer")
   root.addObject('RequiredPlugin', pluginName="Sofa.Component.Topology.Container.Constant")
   root.addObject('RequiredPlugin', pluginName="Sofa.GL.Component.Rendering3D")
   root.addObject('DefaultAnimationLoop', )

   reference = root.addChild('Reference')

   reference.addObject('MeshOBJLoader', name="meshLoader_0", filename="mesh/truthcylinder1-bent.obj", scale="0.95", handleSeams="1")
   reference.addObject('OglModel', src="@meshLoader_0", dx="0", dy="-1", dz="0", color="green")

   springs = root.addChild('Springs')

   springs.addObject('NewmarkIntegrationScheme', rayleighMass="0", rayleighStiffness="0.1")
   springs.addObject('SparseLDLSolver', )
   springs.addObject('MeshGmshLoader', name="loader", filename="mesh/truthcylinder1.msh")
   springs.addObject('MeshTopology', src="@loader")
   springs.addObject('MechanicalObject', src="@loader", dx="15")
   springs.addObject('UniformMass', totalMass="15")
   springs.addObject('FixedProjectiveConstraint', indices="0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 268 269 270 271 343 345")
   springs.addObject('MeshSpringForceField', name="Spring", tetrasStiffness="1870", tetrasDamping="0")

   node = Springs.addChild('node')

   node.addObject('MeshOBJLoader', name="meshLoader_3", filename="mesh/truthcylinder1.obj", handleSeams="1")
   node.addObject('OglModel', name="Visual", src="@meshLoader_3", color="yellow", dx="15")
   node.addObject('BarycentricMapping', input="@..", output="@Visual")

   co_fem = root.addChild('CoFEM')

   co_fem.addObject('NewmarkIntegrationScheme', rayleighMass="0", rayleighStiffness="0.1")
   co_fem.addObject('CGLinearSolver', iterations="100", tolerance="1e-5", threshold="1e-5")
   co_fem.addObject('MeshGmshLoader', name="loader", filename="mesh/truthcylinder1.msh")
   co_fem.addObject('MeshTopology', src="@loader")
   co_fem.addObject('MechanicalObject', src="@loader", dx="30")
   co_fem.addObject('UniformMass', totalMass="15")
   co_fem.addObject('FixedProjectiveConstraint', indices="0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 268 269 270 271 343 345")
   co_fem.addObject('TetrahedronFEMForceField', name="FEM", youngModulus="1116", poissonRatio="0.49", method="polar")

   node = CoFEM.addChild('node')

   node.addObject('MeshOBJLoader', name="meshLoader_2", filename="mesh/truthcylinder1.obj", handleSeams="1")
   node.addObject('OglModel', name="Visual", src="@meshLoader_2", color="cyan", dx="30")
   node.addObject('BarycentricMapping', input="@..", output="@Visual")

   linear_fem = root.addChild('LinearFEM')

   linear_fem.addObject('NewmarkIntegrationScheme', rayleighMass="0", rayleighStiffness="0.1")
   linear_fem.addObject('CGLinearSolver', iterations="100", tolerance="1e-5", threshold="1e-5")
   linear_fem.addObject('MeshGmshLoader', name="loader", filename="mesh/truthcylinder1.msh")
   linear_fem.addObject('MeshTopology', src="@loader")
   linear_fem.addObject('MechanicalObject', src="@loader", dx="45")
   linear_fem.addObject('UniformMass', totalMass="15")
   linear_fem.addObject('FixedProjectiveConstraint', indices="0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 268 269 270 271 343 345")
   linear_fem.addObject('TetrahedronFEMForceField', name="FEM", youngModulus="1116", poissonRatio="0.49", method="small")

   node = LinearFEM.addChild('node')

   node.addObject('MeshOBJLoader', name="meshLoader_1", filename="mesh/truthcylinder1.obj", handleSeams="1")
   node.addObject('OglModel', name="Visual", src="@meshLoader_1", color="red", dx="45")
   node.addObject('BarycentricMapping', input="@..", output="@Visual")