# 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 − (μfast−μslow) ⋅ e−transRate ⋅ |v|</math>
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.