State Relations

rsfmodel.staterelations

class rsfmodel.staterelations.DieterichState

Bases: rsfmodel.staterelations.StateRelation

The slowness or Dieterich state relation as proposed by [1].

Notes

\[\frac{d\theta}{dt} = 1 - \frac{V_\text{slider} \theta}{D_c}\]
[1]Dieterich, J. “Modeling of rock friction: 1. Experimental results and constitutive equations.” Journal of Geophysical Research: Solid Earth (19782012) 84.B5 (1979): 2161-2168.

Methods

evolve_state(system)
set_steady_state(system)
class rsfmodel.staterelations.NagataState

Bases: rsfmodel.staterelations.StateRelation

The Nagata state relation as proposed by [2]:

Notes

\[\frac{d\theta}{dt} = 1 - \frac{V_\text{slider} \theta}{D_c} - \frac{c}{b}\theta\frac{d\mu}{dt}\]
[2]Nagata, K., Nakatani, M., Yoshida, S., “A revised rate-and-state -dependent friction law obtained by constraining constitutive and evolution laws separately with laboratory data,” Journal of Geophysical Research: Solid Earth, vol 117, 2012.

Methods

evolve_state(system)
set_steady_state(system)
class rsfmodel.staterelations.PrzState

Bases: rsfmodel.staterelations.StateRelation

The PRZ state relation as proposed by [3]:

Notes

\[\frac{d\theta}{dt} = 1 - \left(\frac{V_\text{slider} \theta}{2D_c}\right) ^2\]
[3]Perrin, G., Rice, J., and Zheng, G. “Self-healing slip pulse on a frictional surface.” Journal of the Mechanics and Physics of Solids 43.9 (1995): 1461-1495.

Methods

evolve_state(system)
set_steady_state(system)
velocity_component(system)

Perrin-Rice velocity contribution

\[V_\text{contribution} = b \text{ln}\left(V_{\text{prz}0} \theta\right)\]
class rsfmodel.staterelations.RuinaState

Bases: rsfmodel.staterelations.StateRelation

The slip or Ruina state relation as proposed by [4].

Notes

\[\frac{d heta}{dt} = -\frac{V_\text{slider} \theta}{D_c} \text{ln}\left(\frac{V_\text{slider} \theta}{D_c}\right)\]
[4]Ruina, Andy. “Slip instability and state variable friction laws.” J. geophys. Res 88.10 (1983): 359-10.

Methods

evolve_state(system)
set_steady_state(system)
class rsfmodel.staterelations.StateRelation

Bases: object

Abstract state relation object that contains the generally used atributes in state relations (b,Dc).

Attributes

b (float) Rate and state empirical parameter b.
Dc (float) Critical slip distance.
state (float) State variable.

Methods

velocity_component(system)

General velocity contribution from a given state variable

Notes

\[V_\text{contribution} = b \text{ln}\left(\frac{V_0 \theta}{D_c}\right)\]