[cig-commits] r18580 - short/3D/PyLith/trunk/doc/userguide/boundaryconditions

[brad at geodynamics.org]

Author: brad
Date: 2011-06-10 10:53:52 -0700 (Fri, 10 Jun 2011)
New Revision: 18580

Modified:
   short/3D/PyLith/trunk/doc/userguide/boundaryconditions/boundaryconditions.lyx
Log:
Added documentation for time-weakening friction.

Modified: short/3D/PyLith/trunk/doc/userguide/boundaryconditions/boundaryconditions.lyx
===================================================================
--- short/3D/PyLith/trunk/doc/userguide/boundaryconditions/boundaryconditions.lyx	2011-06-10 17:45:06 UTC (rev 18579)
+++ short/3D/PyLith/trunk/doc/userguide/boundaryconditions/boundaryconditions.lyx	2011-06-10 17:53:52 UTC (rev 18580)
@@ -5056,9 +5056,9 @@
 \end_layout
 
 \begin_layout Standard
-PyLith provides three fault constitutive models.
+PyLith provides four fault constitutive models.
  Future releases may contain additional models and a template is provided
- for you to construct your own fault constitutive models (see Section 
+ for you to construct your own (see Section 
 \begin_inset CommandInset ref
 LatexCommand ref
 reference "sec:Extending:FaultConstitutiveModels"
@@ -5272,7 +5272,7 @@
 
 .
  As long as the fault is locked, the initial state variables are zero, so
- specifying the initial state variables for slip-weakening friction is rate.
+ specifying the initial state variables for slip-weakening friction is rare.
 \end_layout
 
 \begin_layout Standard
@@ -5570,6 +5570,300 @@
 \end_layout
 
 \begin_layout Paragraph
+Time-Weakening Friction
+\end_layout
+
+\begin_layout Standard
+The linear time-weakening friction model is analogous to the linear slip-weakeni
+ng friction model with time replacing slip.
+ It produces shear tractions equal to the cohesive stress plus a contribution
+ proportional to the fault normal traction that decreases from a static
+ value to a dynamic value as time progresses,
+\begin_inset Formula 
+\begin{equation}
+T_{f}=\begin{cases}
+T_{c}-(\mu_{s}-(\mu_{s}-\mu_{d})\frac{t}{t_{0}})T_{n} & t\leq t_{0}\text{ and }T_{n}\leq0\\
+T_{c}-\mu_{d}T_{n} & t>t_{0}\text{ and }T_{n}\leq0\\
+0 & T_{n}>0
+\end{cases}
+\end{equation}
+
+\end_inset
+
+The spatial database files for the time-weakening friction model properties
+ and state variables specify the spatial variation of the fault constitutive
+ model parameters given in Table 
+\begin_inset CommandInset ref
+LatexCommand ref
+reference "tab:time:weakening:properties:statevars"
+
+\end_inset
+
+.
+ As long as the fault is locked, the initial state variable is zero, so
+ specifying the initial state variable for time-weakening friction is rare.
+\end_layout
+
+\begin_layout Standard
+\noindent
+\align center
+\begin_inset Float table
+placement H
+wide false
+sideways false
+status open
+
+\begin_layout Plain Layout
+\noindent
+\align center
+\begin_inset Caption
+
+\begin_layout Plain Layout
+\begin_inset CommandInset label
+LatexCommand label
+name "tab:time:weakening:properties:statevars"
+
+\end_inset
+
+Values in spatial databases for time-weakening friction.
+\end_layout
+
+\end_inset
+
+
+\begin_inset VSpace defskip
+\end_inset
+
+
+\begin_inset Tabular
+<lyxtabular version="3" rows="6" columns="3">
+<features tabularvalignment="middle">
+<column alignment="left" valignment="top" width="0">
+<column alignment="left" valignment="top" width="0">
+<column alignment="left" valignment="top" width="2.5in">
+<row>
+<cell alignment="center" valignment="top" topline="true" bottomline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Plain Layout
+
+\series bold
+Database
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" bottomline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Plain Layout
+
+\series bold
+Value
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" bottomline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Plain Layout
+
+\series bold
+Description
+\end_layout
+
+\end_inset
+</cell>
+</row>
+<row>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Plain Layout
+db_properties
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Plain Layout
+
+\family typewriter
+static-coefficient
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Plain Layout
+Static coefficient of friction, 
+\begin_inset Formula $\mu_{s}$
+\end_inset
+
+
+\end_layout
+
+\end_inset
+</cell>
+</row>
+<row>
+<cell alignment="center" valignment="top" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Plain Layout
+
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Plain Layout
+
+\family typewriter
+dynamic-coefficient
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Plain Layout
+Dynamic coefficient of friction, 
+\begin_inset Formula $\mu_{d}$
+\end_inset
+
+
+\end_layout
+
+\end_inset
+</cell>
+</row>
+<row>
+<cell alignment="center" valignment="top" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Plain Layout
+
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Plain Layout
+
+\family typewriter
+time-weakening-parameter
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Plain Layout
+Time-weakening parameter, 
+\begin_inset Formula $t_{0}$
+\end_inset
+
+
+\end_layout
+
+\end_inset
+</cell>
+</row>
+<row>
+<cell alignment="center" valignment="top" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Plain Layout
+
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Plain Layout
+
+\family typewriter
+cohesion
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Plain Layout
+Cohesive stress, 
+\begin_inset Formula $T_{c}$
+\end_inset
+
+
+\end_layout
+
+\end_inset
+</cell>
+</row>
+<row>
+<cell alignment="center" valignment="top" topline="true" bottomline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Plain Layout
+db_initial_state
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" bottomline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Plain Layout
+
+\family typewriter
+elapsed-time
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" bottomline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Plain Layout
+Elasped time of slip, 
+\begin_inset Formula $t$
+\end_inset
+
+
+\end_layout
+
+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
+\end_inset
+
+
+\end_layout
+
+\end_inset
+
+
+\end_layout
+
+\begin_layout Paragraph
 Rate- and State-Friction with Ageing Law
 \end_layout