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Node1D

A node with one :ref:`ODE2 <ODE2>` coordinate for one dimensional (1D) problems; use e.g. for scalar dynamic equations (Mass1D) and mass-spring-damper mechanisms, representing either translational or rotational degrees of freedom: in most cases, Node1D is equivalent to NodeGenericODE2 using one coordinate, however, it offers a transformation to 3D translational or rotational motion and allows to couple this node to 2D or 3D bodies.

Additional information for Node1D:

  • This Node has/provides the following types = GenericODE2

The item Node1D with type = '1D' has the following parameters:

  • name [type = String, default = '']:
    node's unique name
  • referenceCoordinates [[q_0]\tp\cRef, type = Vector, default = [0.]]:
    reference coordinate of node (in vector form)
  • initialCoordinates [[q_0]\tp\cIni, type = Vector, default = [0.]]:
    initial displacement coordinate (in vector form)
  • initialVelocities [[\dot q_0]\tp\cIni, type = Vector, default = [0.]]:
    initial velocity coordinate (in vector form)
  • visualization [type = VNode1D]:
    parameters for visualization of item

The item VNode1D has the following parameters:

  • show [type = Bool, default = False]:
    set true, if item is shown in visualization and false if it is not shown; The node1D is represented as reference position and displacement along the global x-axis, which must not agree with the representation in the object using the Node1D

DESCRIPTION of Node1D

The following output variables are available as OutputVariableType in sensors, Get...Output() and other functions:

  • Coordinates: {\mathbf{q}}\cConfig = [q_0]\tp\cConfig
    :ref:`ODE2 <ODE2>` coordinate of node (in vector form)
  • Coordinates\_t: \dot {\mathbf{q}}\cConfig = [\dot q_0]\tp\cConfig
    :ref:`ODE2 <ODE2>` velocity coordinate of node (in vector form)
  • Coordinates\_tt: \ddot {\mathbf{q}}\cConfig = [\ddot q_0]\tp\cConfig
    :ref:`ODE2 <ODE2>` acceleration coordinate of node (in vector form)

Detailed information: The current position/rotation coordinate of the 1D node is computed from

p_0 = {q_0}\cRef + {q_0}\cCur

The coordinate leads to one second order differential equation. The graphical representation and the (internal) position of the node is

p\cConfig= \vr{{p_0}\cConfig}{0}{0}

The (internal) velocity vector is [{p_0}\cConfig,\,0,\,0]\tp.

Relevant Examples and TestModels with weblink:

lugreFrictionTest.py (Examples/), mpi4pyExample.py (Examples/), multiprocessingTest.py (Examples/), nMassOscillator.py (Examples/), nMassOscillatorEigenmodes.py (Examples/), nMassOscillatorInteractive.py (Examples/), coordinateSpringDamperExt.py (TestModels/), distanceSensor.py (TestModels/), driveTrainTest.py (TestModels/)

The web version may not be complete. For details, consider also the Exudyn PDF documentation : theDoc.pdf