ObjectMassPoint
A 3D mass point which is attached to a position-based node, usually NodePoint.
Additional information for ObjectMassPoint:
- This
Object
has/provides the following types =Body
,SingleNoded
- Requested
Node
type =Position
- Short name for Python =
MassPoint
- Short name for Python visualization object =
VMassPoint
The item ObjectMassPoint with type = ‘MassPoint’ has the following parameters:
- name [type = String, default = ‘’]:objects’s unique name
- physicsMass [
, type = UReal, default = 0.]:mass [SI:kg] of mass point - nodeNumber [
, type = NodeIndex, default = invalid (-1)]:node number (type NodeIndex) for mass point - visualization [type = VObjectMassPoint]:parameters for visualization of item
The item VObjectMassPoint has the following parameters:
- show [type = Bool, default = True]:set true, if item is shown in visualization and false if it is not shown
- graphicsData [type = BodyGraphicsData]:Structure contains data for body visualization; data is defined in special list / dictionary structure
DESCRIPTION of ObjectMassPoint
The following output variables are available as OutputVariableType in sensors, Get…Output() and other functions:
Position
:global position vector of translated local position; local (body) coordinate system = global coordinate systemDisplacement
:global displacement vector of mass pointVelocity
:global velocity vector of mass pointAcceleration
:global acceleration vector of mass point
Definition of quantities
intermediate variables
|
symbol
|
description
|
---|---|---|
node position
|
position of mass point which is provided by node
|
|
node displacement
|
displacement of mass point which is provided by node
|
|
node velocity
|
velocity of mass point which is provided by node
|
|
transformation matrix
|
transformation of local body (
|
|
residual forces
|
residual of all forces on mass point
|
|
applied forces
|
applied forces (loads, connectors, joint reaction forces, …)
|
Equations of motion
For example, a LoadCoordinate on coordinate 1 of the node would add a term in
Position-based markers can measure position
transforms the action of global applied forces
MINI EXAMPLE for ObjectMassPoint
1node = mbs.AddNode(NodePoint(referenceCoordinates = [1,1,0],
2 initialCoordinates=[0.5,0,0],
3 initialVelocities=[0.5,0,0]))
4mbs.AddObject(MassPoint(nodeNumber = node, physicsMass=1))
5
6#assemble and solve system for default parameters
7mbs.Assemble()
8mbs.SolveDynamic()
9
10#check result
11exudynTestGlobals.testResult = mbs.GetNodeOutput(node, exu.OutputVariableType.Position)[0]
12#final x-coordinate of position shall be 2
Relevant Examples and TestModels with weblink:
interactiveTutorial.py (Examples/), ComputeSensitivitiesExample.py (Examples/), coordinateSpringDamper.py (Examples/), massSpringFrictionInteractive.py (Examples/), minimizeExample.py (Examples/), nMassOscillator.py (Examples/), nMassOscillatorInteractive.py (Examples/), parameterVariationExample.py (Examples/), particleClusters.py (Examples/), particlesSilo.py (Examples/), particlesTest.py (Examples/), particlesTest3D.py (Examples/), complexEigenvaluesTest.py (TestModels/), connectorGravityTest.py (TestModels/), contactCoordinateTest.py (TestModels/)
The web version may not be complete. For details, consider also the Exudyn PDF documentation : theDoc.pdf