This information is part of the Modelica Standard Library maintained by the Modelica Association.

UniversalSpherical

Universal - spherical joint aggregation (1 constraint, no potential states)

Information
CONNECTORS
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NameTypeDescription
frame_aFrame_aCoordinate system fixed to the component with one cut-force and cut-torque
frame_bFrame_bCoordinate system fixed to the component with one cut-force and cut-torque
frame_iaFrame_aCoordinate system at the origin of frame_a, fixed at the rod connecting the universal with the spherical joint
PARAMETERS
NameTypeDefault ValueDescription
animationBooleantrue= true, if animation shall be enabled
showUniversalAxesBooleantrue = true, if universal joint shall be visualized with two cylinders, otherwise with a sphere (provided animation=true)
computeRodLengthBooleanfalse= true, if distance between frame_a and frame_b shall be computed during initialization (see info)
n1_aAxis{0,0,1}Axis 1 of universal joint resolved in frame_a (axis 2 is orthogonal to axis 1 and to rod)
rRod_iaPosition[3]{1,0,0}Vector from origin of frame_a to origin of frame_b, resolved in frame_ia (if computeRodLength=true, rRod_ia is only an axis vector along the connecting rod)
sphereDiameterDiameterworld.defaultJointLengthDiameter of spheres representing the universal and the spherical joint
rodShapeTypeShapeType"cylinder"Shape type of rod connecting the universal and the spherical joint
rodWidthDistancesphereDiameter/Types.Defaults.JointRodDiameterFractionWidth of rod shape in direction of axis 2 of universal joint.
rodHeightDistancerodWidthHeight of rod shape in direction that is orthogonal to rod and to axis 2
rodExtraShapeExtra0.0Additional parameter depending on rodShapeType
cylinderLengthDistanceworld.defaultJointLengthLength of cylinders representing the two universal joint axes
cylinderDiameterDistanceworld.defaultJointWidthDiameter of cylinders representing the two universal joint axes
kinematicConstraintBooleantrue= false, if no constraint shall be defined, due to analytically solving a kinematic loop
checkTotalPowerBooleanfalse= true, if total power flowing into this component shall be determined (must be zero)
rodLengthDistanceModelica.Math.Vectors.length(rRod_ia)Length of rod (distance between origin of frame_a and origin of frame_b)
eRod_iaReal[3]Modelica.Math.Vectors.normalize(rRod_ia)Unit vector from origin of frame_a to origin of frame_b, resolved in frame_ia
e2_iaReal[3]Modelica.Math.Vectors.normalize(cross(n1_a, eRod_ia))Unit vector in direction of axis 2 of universal joint, resolved in frame_ia (orthogonal to n1_a and eRod_ia; note: frame_ia is parallel to frame_a when the universal joint angles are zero)
e3_iaReal[3]cross(eRod_ia, e2_ia)Unit vector perpendicular to eRod_ia and e2_ia, resolved in frame_ia
USED IN EXAMPLES
Modelica.Mechanics.MultiBody.Examples.Loops.Fourbar2
One kinematic loop with four bars (with UniversalSpherical joint; 1 non-linear equation)
USED IN COMPONENTS
Modelica.Mechanics.MultiBody.Joints.Assemblies.JointUSR
Universal - spherical - revolute joint aggregation (no constraints, no potential states)
Modelica.Mechanics.MultiBody.Joints.Assemblies.JointUSP
Universal - spherical - prismatic joint aggregation (no constraints, no potential states)