WorldForceAndTorque
External force and torque acting at frame_b, defined by 3+3 input signals and resolved in frame world, frame_b or in frame_resolve
Library
Modelica/Mechanics/MultiBody/Forces
Description
The 3 signals of the force and torqueconnector are interpretedas the x-, y- and z-coordinates of a force andtorque acting at the frameconnector to which frame_b of this component is attached.Via parameter resolveInFrame it is defined, in which frame thesecoordinates shall be resolved:
| Types.ResolveInFrameB. | Meaning |
|---|---|
| world | Resolve input force and torque in world frame (= default) |
| frame_b | Resolve input force and torque in frame_b |
| frame_resolve | Resolve input force and torque in frame_resolve (frame_resolve must be connected) |
If resolveInFrame = Types.ResolveInFrameB.frame_resolve, the force andtorque coordinatesare with respect to the frame, that is connected to frame_resolve.
If force={100,0,0}, and for all parameters the default setting is used,then the interpretation is that a force of 100 N is acting along the positivex-axis of frame_b.
Conceptually, a force and torque acts on the world frame in such a way thatthe force and torque balance between world.frame_b and frame_b is fulfilled.For efficiency reasons, this reaction torque is, however, not computed.
The force and torque are by default visualized as an arrow (force)and as a double arrow (torque) acting at the connector to whichthey are connected. The diametersand colors of the arrows can be defined viavariables forceDiameter, torqueDiameter,forceColor and torqueColor. The arrowspoint in the directions defined by theforce and torque vectors. The lengths of the arrows are proportionalto the length of the force and torque vectors, respectively, using parametersN_to_m and Nm_to_m as scaling factors. For example, if N_to_m = 100 N/m,then a force of 350 N is displayed as an arrow of length 3.5 m.
An example how to use this model is given in thefollowing figure:
This leads to the following animation
Parameters
| Name | Label | Description | Data Type | Valid Values |
|---|---|---|---|---|
mo_animation | animation | = true, if animation shall be enabled | Scalar | true |
mo_resolveInFrame | resolveInFrame | Frame in which input force and torque are resolved (1: world, 2: frame_b, 3: frame_resolve) | Structure | |
mo_resolveInFrame/choice1 | Resolve in world frame | Number | 0 | |
mo_resolveInFrame/choice2 | Resolve in frame_b | Number | 0 | |
mo_resolveInFrame/choice3 | Resolve in frame_resolve (frame_resolve must be connected) | Number | 0 | |
mo_N_to_m | N_to_m | Force arrow scaling (length = force/N_to_m) | Scalar | |
mo_Nm_to_m | Nm_to_m | Torque arrow scaling (length = torque/Nm_to_m) | Scalar | |
mo_forceDiameter | forceDiameter | Diameter of force arrow | Scalar | |
mo_torqueDiameter | torqueDiameter | Diameter of torque arrow | Scalar | |
mo_forceColor | forceColor | Color of force arrow | Vector of size 3 | |
mo_torqueColor | torqueColor | Color of torque arrow | Vector of size 3 | |
mo_specularCoefficient | specularCoefficient | Reflection of ambient light (= 0: light is completely absorbed) | Scalar |
| Name | Label | Description | Data Type | Valid Values |
|---|---|---|---|---|
mo__nmodifiers | Number of Modifiers | Specifies the number of modifiers | Number | |
mo__modifiers | Modifiers | Add new modifier | Structure | |
mo__modifiers/varname | Variable name | Cell of strings | 'f_in_m' | |
mo__modifiers/attribute | Attribute | Cell of strings | 'start' | |
mo__modifiers/value | Value |
Ports
| Name | Type | Description | IO Type | Number |
|---|---|---|---|---|
frame_b | implicit | Coordinate system fixed to the component with one cut-force and cut-torque | output | 1 |
force | implicit | x-, y-, z-coordinates of force resolved in frame defined by resolveInFrame | input | 1 |
torque | implicit | x-, y-, z-coordinates of torque resolved in frame defined by resolveInFrame | input | 2 |
Port 4 | implicit | The input signals are optionally resolved in this frame | output | mo_resolveInFrame.choice3 |