# Velocity Dependent Friction

This command is used to construct a VelDependent friction model object. It is useful for modeling the behavior of [http://en.wikipedia.org/wiki/Polytetrafluoroethylene"PTFE"] or PTFE-like materials sliding on a stainless steel surface. For a detailed presentation on the velocity dependence of such interfaces please refer to Constantinou et al. (1999).

```tcl frictionModel VelDependent $frnTag $muSlow $muFast $transRate ```
frnTag

unique friction model object tag

muSlow

coefficient of friction at low velocity

muFast

coefficient of friction at high velocity

transRate

transition rate from low to high velocity

<math>μ = μfast − (μfastμslow) ⋅ etransRate ⋅ |v|</math>

VDependentFriction01.png
VDependentFrictionCurveFit.png

## Examples

frictionModel VelDependent 1 0.05 0.163 0.615


REFERENCE:

Constantinou, M.C., Tsopelas, P., Kasalanati, A., and Wolff, E.D. (1999). “Property modification factors for seismic isolation bearings”. Report MCEER-99-0012, Multidisciplinary Center for Earthquake Engineering Research, State University of New York.


RELATED TO:


Code Developed by: Andreas Schellenberg, University of California, Berkeley.