WOLFRAM SYSTEMMODELER
Frame_aCoordinate system fixed to the component with one cutforce and cuttorque (filled rectangular icon) 
SystemModel["Modelica.Mechanics.MultiBody.Interfaces.Frame_a"]
This information is part of the Modelica Standard Library maintained by the Modelica Association.
Basic definition of a coordinate system that is fixed to a mechanical component. In the origin of the coordinate system the cutforce and the cuttorque is acting. This component has a filled rectangular icon.
R 
Type: Orientation Description: Orientation object to rotate the world frame into the connector frame 

Point mass used at all places of this example 

Body used at all places of the comparison model with zero inertia tensor 

Cylinder with rod and crank of a combustion engine 

One cylinder with analytic handling of kinematic loop 

One cylinder with analytic handling of kinematic loop and CAD visualization 

V6 engine with analytic loop handling 

Cylinder type 

Force acting between two frames, defined by 3 input signals and resolved in frame world, frame_a, frame_b or frame_resolve 

Torque acting between two frames, defined by 3 input signals and resolved in frame world, frame_a, frame_b or frame_resolve 

Force and torque acting between two frames, defined by 3+3 input signals and resolved in frame world, frame_a, frame_b or frame_resolve 

General line force component with an optional point mass on the connection line 

General line force component with two optional point masses on the connection line 

Linear translational spring with optional mass 

Linear (velocity dependent) damper 

Linear spring and linear damper in parallel 

Linear spring and linear damper in series connection 

Force acting between two frames, defined by 3 input signals 

Torque acting between two frames, defined by 3 input signals 

Adaptor to allow direct connections to the subconnectors of FlangeWithBearing 

Base model for components providing two frame connectors + outer world + assert to guarantee that the component is connected 

Base model for components providing two frame connectors + outer world + assert to guarantee that the component is connected (default icon size is factor 2 larger as usual) 

Base model for components providing one frame_a connector + outer world + assert to guarantee that the component is connected 

Base model for elementary joints (has two frames + outer world + assert to guarantee that the joint is connected) 

Base model for force elements (provide frame_b.f and frame_b.t in subclasses) 

Base model for line force elements 

Base model to measure an absolute frame variable 

Base model to measure a relative variable between two frames 

Base model for visualizers (has a frame_a on the left side + outer world + assert to guarantee that the component is connected) 

Prismatic joint (1 translational degreeoffreedom, 2 potential states, optional axis flange) 

Revolute joint (1 rotational degreeoffreedom, 2 potential states, optional axis flange) 

Revolute joint that is described by 2 positional constraints for usage in a planar loop (the ambiguous cutforce perpendicular to the loop and the ambiguous cuttorques are set arbitrarily to zero) 

Cylindrical joint (2 degreesoffreedom, 4 potential states) 

Universal joint (2 degreesoffreedom, 4 potential states) 

Planar joint (3 degreesoffreedom, 6 potential states) 

Spherical joint (3 constraints and no potential states, or 3 degreesoffreedom and 3 states) 

Free motion joint (6 degreesoffreedom, 12 potential states) 

Free motion joint with scalar initialization and state selection (6 degreesoffreedom, 12 potential states) 

Spherical  spherical joint aggregation (1 constraint, no potential states) with an optional point mass in the middle 

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

Ideal 3dim. gearbox (arbitrary shaft directions) 

Joint (no mass, no inertia) that describes an ideal rolling wheel (rolling on the plane z=0) 

Joint (no mass, no inertia) that describes an ideal rolling wheel set (two ideal rolling wheels connected together by an axis) 

Universal  prismatic  spherical joint aggregation (no constraints, no potential states) 

Universal  spherical  revolute joint aggregation (no constraints, no potential states) 

Universal  spherical  prismatic joint aggregation (no constraints, no potential states) 

Spherical  spherical  revolute joint aggregation with mass (no constraints, no potential states) 

Spherical  spherical  prismatic joint aggregation with mass (no constraints, no potential states) 

Planar revolute  revolute  revolute joint aggregation (no constraints, no potential states) 

Planar revolute  revolute  prismatic joint aggregation (no constraints, no potential states) 

Prismatic cutjoint and translational directions may be constrained or released 

Revolute cutjoint and translational directions may be constrained or released 

Spherical cut joint and translational directions may be constrained or released 

Universal cutjoint and translational directions may be constrained or released 

Revolute joint where the rotation angle is computed from a length constraint (1 degreeoffreedom, no potential state) 

Prismatic joint where the translational distance is computed from a length constraint (1 degreeoffreedom, no potential state) 

RollingConstraintVerticalWheel Rolling constraint for wheel that is always perpendicular to xy plane 

Internal model to initialize the angels for Joints.FreeMotionScalarInit 

Fixed translation of frame_b with respect to frame_a 

Fixed translation followed by a fixed rotation of frame_b with respect to frame_a 

Rigid body with mass, inertia tensor and one frame connector (12 potential states) 

Rigid body with mass, inertia tensor, different shapes for animation, and two frame connectors (12 potential states) 

Rigid body with box shape. Mass and animation properties are computed from box data and density (12 potential states) 

Rigid body with cylinder shape. Mass and animation properties are computed from cylinder data and density (12 potential states) 

Rigid body where body rotation and inertia tensor is neglected (6 potential states) 

Propagate 1dim. support torque to 3dim. system (provided world.driveTrainMechanics3D=true) 

1D inertia attachable on 3dim. bodies (3D dynamic effects are taken into account if world.driveTrainMechanics3D=true) 

1D inertia attachable on 3dim. bodies (3D dynamic effects are taken into account) 

1D gearbox with arbitrary shaft directions and 3dim. bearing frame (3D dynamic effects are taken into account provided world.driveTrainMechanics3D=true) 

Ideal rolling wheel on flat surface z=0 (5 positional, 3 velocity degrees of freedom) 

Ideal rolling wheel set consisting of two ideal rolling wheels connected together by an axis 

Measure absolute kinematic quantities of frame connector 

Measure relative kinematic quantities between two frame connectors 

Measure absolute position vector of the origin of a frame connector 

Measure absolute velocity vector of origin of frame connector 

Measure absolute angles between frame connector and the world frame 

Measure absolute angular velocity of frame connector 

Measure relative position vector between the origins of two frame connectors 

Measure relative velocity vector between the origins of two frame connectors 

Measure relative angles between two frame connectors 

Measure relative angular velocity between two frame connectors 

Measure the distance between the origins of two frame connectors 

Measure cut force vector 

Measure cut torque vector 

Measure cut force and cut torque vector 

Measure power flowing from frame_a to frame_b 

Transform absolute vector in to another frame 

Transform relative vector in to another frame 

Partial absolute sensor model for sensors defined by components 

Partial absolute sensor models for sensors defined by equations (frame_resolve must be connected exactly once) 

Partial relative sensor model for sensors defined by components 

Partial relative sensor models for sensors defined by equations (frame_resolve must be connected exactly once) 

Measure absolute position vector (same as Sensors.AbsolutePosition, but frame_resolve is not conditional and must be connected) 

Measure absolute angular velocity 

Measure relative position vector (same as Sensors.RelativePosition, but frame_resolve is not conditional and must be connected) 

Measure relative angular velocity 

Transform absolute vector in to another frame 

Transform relative vector in to another frame 

Set force and torque to zero 

Base model to measure the cut force and/or torque between two frames, defined by components 

Base model to measure the cut force and/or torque between two frames, defined by equations (frame_resolve must be connected exactly once) 

Measure cut force vector (frame_resolve must be connected) 

Measure cut torque vector (frame_resolve must be connected) 

Obsolete model will be removed in future versions, use TransformAbsoluteVector instead! 

Obsolete model will be removed in future versions, use TransformRelativeVector instead! 

Visualizing an elementary shape with dynamically varying shape attributes (has one frame connector) 

Visualizing an elementary shape with dynamically varying shape attributes (has two frame connectors) 

Visualizing a coordinate system including axes labels (visualization data may vary dynamically) 

Visualizing an arrow with dynamically varying size in frame_a 

Visualizing an arrow with dynamically varying size in frame_a based on input signal 

Visualizing a torus 

Visualizing a voluminous wheel 

Visualizing a pipe with scalar field quantities along the pipe axis 

Visualizing a set of lines as cylinders (e.g., used to display characters) 