Translational Friction
Purpose
Ideal translational stick/slip friction
Library
Mechanical / Translational / Components
Description
The Translational Friction models any combination of static, Coulomb and viscous friction between two flanges in a translational system. While the component is stuck, it exerts whatever force is necessary in order to maintain zero relative speed between the flanges, up to the limit of the breakaway force \(F_{\mathrm{brk}}\). When the breakaway force is exceeded, the flanges begin sliding against each other, and the component exerts a force that consists of the Coulomb friction force \(F_{\mathrm{C}}\) and a speed-dependent viscous friction force \(c_\mathrm{v} \cdot v\).
Fig. 282 shows the speed/force characteristic and the state chart of the component. Note that the friction force is opposed to the movement, hence the negative sign.
Fig. 282 Translational friction speed/force characteristic and state chart
Parameters
- Breakaway friction force
The maximum magnitude of the stiction force \(F_{\mathrm{brk}}\), in newtons \((\mathrm{N})\). Must be greater than or equal to zero.
- Coulomb friction force
The magnitude of the (constant) Coulomb friction force \(F_{\mathrm{C}}\), in newtons \((\mathrm{N})\). Must be greater than or equal to zero and less than or equal to the breakaway friction force.
- Viscous friction coefficient
The proportionality coefficient \(c_\mathrm{v}\) that determines the speed dependent viscous friction force, in \((\frac{\mathrm{Ns}}{\mathrm{m}})\).
Probe Signals
- Force
The transmitted force \(F\) flowing from the unmarked to the marked flange, in newtons \((\mathrm{N})\).
- Speed
The speed \(v\) of the marked flange with respect to the unmarked flange, in \((\frac{\mathrm{m}}{\mathrm{s}})\).
- State
The internal state of the component:
-1sliding backward,0stuck,+1sliding forward.