[cig-commits] r13662 - doc/snac
echoi at geodynamics.org
echoi at geodynamics.org
Fri Dec 12 07:20:18 PST 2008
Author: echoi
Date: 2008-12-12 07:20:18 -0800 (Fri, 12 Dec 2008)
New Revision: 13662
Modified:
doc/snac/snac.lyx
Log:
Some changes made to the "Benchmarks" chapter.
Modified: doc/snac/snac.lyx
===================================================================
--- doc/snac/snac.lyx 2008-12-12 13:01:26 UTC (rev 13661)
+++ doc/snac/snac.lyx 2008-12-12 15:20:18 UTC (rev 13662)
@@ -2814,14 +2814,18 @@
\begin_layout Description
\family typewriter
-SnacPlSeeds
+SnacPlSeeds/SnacVPSeeds
\family default
: can control the positions of elements that have the initial non-zero plastic
strain.
These elements play the role of seeds where strain localization initiates.
-
+ Used in tandem with SnacPlastic and SnacViscoPlastic, respectively.
\end_layout
+\begin_layout Standard
+Other plugins found in the plugins directory are experimental.
+\end_layout
+
\begin_layout Subsection
Mesh Structure
\end_layout
@@ -2932,7 +2936,9 @@
\begin_inset Quotes srd
\end_inset
- determines the depth from the parallel boundary in terms of the number
+ determines how many elements in one local domain are made to transfer variables
+ to neighbor domains.
+ It takes a non-negative inger value corresponding to the number of layers
of elements.
To run Snac in parallel, this parameter should be 1 or larger.
``
@@ -2992,12 +2998,12 @@
\begin_layout Standard
\begin_inset Formula \begin{equation}
-\eta\left(T,\dot{\varepsilon}\right)=\eta_{0}\dot{\varepsilon}^{\left(1-1/n\right)}\exp\left(\frac{E^{*}}{R}\left(\frac{1}{T}-\frac{1}{T_{0}}\right)\right),\label{eq:functionformviscosity}\end{equation}
+\eta\left(T,\dot{\varepsilon}\right)=\eta_{0}\dot{\varepsilon}^{\left(1/n-1\right)}\exp\left(\frac{E^{*}}{R}\left(\frac{1}{T}-\frac{1}{T_{0}}\right)\right),\label{eq:functionformviscosity}\end{equation}
\end_inset
where
-\begin_inset Formula $\eta_{0}^{}$
+\begin_inset Formula $\eta_{0}$
\end_inset
is ``
@@ -3024,7 +3030,11 @@
\begin_inset Formula $T_{0}$
\end_inset
- is ``reftemp'' (K),
+ is ``reftemp'' (
+\begin_inset Formula $^{\circ}C$
+\end_inset
+
+),
\begin_inset Formula $,\dot{\varepsilon}$
\end_inset
@@ -3070,16 +3080,35 @@
\begin_layout Standard
Plastic parameters can dynamically vary and are approximated by piecewise
linear function of accumulated plastic strain.
- So, the number of linear segments is defined first by nsegments.
- If nsegments is n, n+1 values of parameters are required to define the
- n linear segments.
+ So, the number of linear segments is defined first by
+\family typewriter
+nsegments
+\family default
+.
+ If
+\family typewriter
+nsegments
+\family default
+ is n, n+1 values of parameters are required to define the n linear segments.
\end_layout
\begin_layout Standard
-Plasticity models used in SNAC are Drucker-Prager and Mohr-Coulomb.
- The corresponding parameter name is yieldcriterion, and the legitimate
- values it can assume are druckerprager and mohrcoulomb.
+The working plasticity models in SNAC is Mohr-Coulomb.
+ The Drucker-Prager model has been implemented but not verified.
+ The corresponding parameter name is
+\family typewriter
+yieldcriterion
+\family default
+, and the legitimate values it can assume are
+\family typewriter
+mohrcoulomb
+\family default
+ and
+\family typewriter
+druckerprager
+\family default
+.
\end_layout
@@ -3514,7 +3543,7 @@
\end_layout
\begin_layout LyX-Code
- 500.0</param>
+ 500.0</param> <!-- in degrees Celsius -->
\end_layout
\begin_layout LyX-Code
@@ -3610,62 +3639,6 @@
\end_layout
\begin_layout LyX-Code
- <struct>
-\end_layout
-
-\begin_layout LyX-Code
- <param name="type">
-\end_layout
-
-\begin_layout LyX-Code
- AllElementsVC</param>
-\end_layout
-
-\begin_layout LyX-Code
- <list name="variables">
-\end_layout
-
-\begin_layout LyX-Code
- <struct>
-\end_layout
-
-\begin_layout LyX-Code
- <param name="name">
-\end_layout
-
-\begin_layout LyX-Code
- hydroStatic</param>
-\end_layout
-
-\begin_layout LyX-Code
- <param name="type">
-\end_layout
-
-\begin_layout LyX-Code
- func</param>
-\end_layout
-
-\begin_layout LyX-Code
- <param name="value">
-\end_layout
-
-\begin_layout LyX-Code
- SnacHydroStaticIC_IC</param>
-\end_layout
-
-\begin_layout LyX-Code
- </struct>
-\end_layout
-
-\begin_layout LyX-Code
- </list>
-\end_layout
-
-\begin_layout LyX-Code
- </struct>
-\end_layout
-
-\begin_layout LyX-Code
</list>
\end_layout
@@ -3696,9 +3669,9 @@
\end_layout
\begin_layout Standard
-Two ways of assigning a value to all nodes or elements are available.
- One is to put a single value for the ``value'' member in the lowest-level
- structure as in the next example:
+One way of assigning a value to all nodes or elements is to put a single
+ value for the ``value'' member in the lowest-level structure as in the
+ next example:
\end_layout
\begin_layout LyX-Code
@@ -3733,6 +3706,19 @@
</struct>
\end_layout
+\begin_layout Standard
+The other way is to define a
+\emph on
+condition function
+\emph default
+ and assign ``func
+\begin_inset Quotes srd
+\end_inset
+
+ to type and the function's name to value.
+ More details are given in the next section.
+\end_layout
+
\begin_layout Subsection
\begin_inset LatexCommand label
name "sub:Boundary-Conditions-Structure"
@@ -3905,7 +3891,7 @@
vel structure.
The other way of applying boundary conditions is to put ``
\family typewriter
-function
+func
\family default
'' in the ``
\family typewriter
@@ -4524,18 +4510,15 @@
\end_layout
\begin_layout LyX-Code
- <param name="type"> AllNodesVC </param>
-
+ <param name="type"> AllNodesVC </param>
\end_layout
\begin_layout LyX-Code
- <list name="variables">
-
+ <list name="variables">
\end_layout
\begin_layout LyX-Code
- <struct>
-
+ <struct>
\end_layout
\begin_layout LyX-Code
@@ -4547,11 +4530,14 @@
\end_layout
\begin_layout LyX-Code
- <param name="value"> SnacTemperature_Top2BottomSweep
- </param> </struct>
+ <param name="value">SnacTemperature_Top2BottomSweep</param>
\end_layout
\begin_layout LyX-Code
+ </struct>
+\end_layout
+
+\begin_layout LyX-Code
</list>
\end_layout
@@ -4584,25 +4570,19 @@
\end_layout
\begin_layout LyX-Code
- <param name="type"> AllElementsVC </param>
-
+ <param name="type"> AllElementsVC </param>
\end_layout
\begin_layout LyX-Code
- <list name="variables">
-
+ <list name="variables">
\end_layout
\begin_layout LyX-Code
<struct>
-
+ <paramname="name">elementMaterial</param>
\end_layout
\begin_layout LyX-Code
- <param name="name"> elementMaterial </param>
-\end_layout
-
-\begin_layout LyX-Code
<param name="type"> int </param>
\end_layout
@@ -5028,7 +5008,7 @@
\begin_layout Standard
SNAC writes binary output files and it is necessary to convert them to a
- file format that visualization tools can handle.
+ file format that external visualization tools can handle.
Two such converting programs are provided.
One is for the open source Open Visualization Data Explorer, better known
as OpenDX.
@@ -5079,12 +5059,25 @@
\end_layout
\begin_layout Standard
-Information on the parallel decompositon is not given in an input file by
- a user.
+Information on the parallel decompositon is not explicitly given in an input
+ file by a user.
Instead, StGermain computes an optimal configuration based on the total
- number of processors and the global mesh size.
+ number of processors, the global mesh size, and the value of
+\family typewriter
+decompDims
+\family default
+.
The resultant local element numbers in x, y, and z (lon, radius, lat) are
- written in the file, sim.0, which are common to all the processors.
+ written in the file,
+\family typewriter
+sim.{processor ID}
+\family default
+, of which contents are common to all the processors.
+ The data in
+\family typewriter
+sim.*
+\family default
+ are used to infer the number of processors in each decomposed axis.
\end_layout
\begin_layout Section
@@ -5102,22 +5095,25 @@
\end_inset
.
- The source code is Snac/snac2dx/snac2dx.c and compiled during the Snac building
- and placed in ${SNAC_BINDIR} together with other executables.
+ The source code is Snac/snac2dx/snac2dx.c and compiled during the Snac's
+ building procedure and placed in ${SNAC_BINDIR} together with other executables.
\end_layout
\begin_layout Standard
Running snac2dx without any arguments converts data for all the time steps
- recorded in timeStep.0.
+ recorded in
+\family typewriter
+timeStep.0
+\family default
+.
Optionally, a range of time steps can be set if two positive integers are
given as arguments.
The converted output files are always written in the directory where snac2dx
is run.
- The naming convention for the ascii dx files is ``snac.{processor ID}.{time
- step in 6 digits}.dx
-\begin_inset Quotes srd
-\end_inset
-
+ The naming convention for the ascii dx files is
+\family typewriter
+snac.{processor ID}.{time step in 6 digits}.dx
+\family default
.
\end_layout
@@ -5136,6 +5132,19 @@
modelname
\series default
: Suffix for the combined data files.
+
+\begin_inset Quotes sld
+\end_inset
+
+
+\family typewriter
+snac
+\family default
+
+\begin_inset Quotes srd
+\end_inset
+
+ unless snac2dx.c is modified.
\end_layout
\begin_layout Itemize
@@ -5196,7 +5205,11 @@
\begin_layout Standard
Let's assume that the global mesh has 51 x 31 x 41 nodes and was decomposed
- in 3D by 8 processors.
+ in 3D (
+\family typewriter
+decompDims
+\family default
+=3) by 8 processors.
Also, we assume that the contents of sim.0 is ``25 15 20
\begin_inset Quotes srd
\end_inset
@@ -5290,7 +5303,6 @@
\end_layout
\begin_layout LyX-Code
-\SpecialChar \ldots{}
\end_layout
@@ -5348,13 +5360,11 @@
\end_layout
\begin_layout Standard
-Problem Description (excerpted from the FLAC3D manual, p.
- G-25) [TODO - reference needed for biblio].
- This problem concerns the determination of stresses in a Mohr-Coulomb material
+This problem concerns the determination of stresses in a Mohr-Coulomb material
subjected to an odometer test.
In this experiment, two of the principal stress components are equal and,
during plastic flow, the stress point evolves along a vertex of the Mohr-Coulom
-b criterion representation in the Pi-plane.
+b criterion representation in the principal stress space.
\end_layout
@@ -5475,8 +5485,15 @@
\end_layout
\begin_layout Itemize
-Stress-strain diagram is made using S_yy and E_yy from both numerical and
- analytic solutions.
+Stress-strain diagram is made using
+\begin_inset Formula $\sigma_{yy}$
+\end_inset
+
+and
+\begin_inset Formula $\epsilon_{yy}$
+\end_inset
+
+ from both numerical and analytic solutions.
\end_layout
@@ -5510,7 +5527,7 @@
\begin_inset Caption
\begin_layout Standard
-TODO need caption
+Stress-strain plot
\end_layout
\end_inset
@@ -5528,12 +5545,6 @@
\end_layout
\begin_layout Standard
-Problem Description: Expansion of a thick cylinder under uniform internal
- pressure.
-
-\end_layout
-
-\begin_layout Standard
A constant and uniform internal pressure is applied to the inner surface
of a thick cylinder without pre-stress.
Taking advantage of symmetry, only a quadrant of the cylinder is modeled.
@@ -5597,31 +5608,9 @@
\end_inset
31 nodes.
-
\end_layout
\begin_layout Itemize
-Use these files to reproduce this result:
-\end_layout
-
-\begin_deeper
-\begin_layout Itemize
-input file:
-\family typewriter
-tresca.xml
-\end_layout
-
-\begin_layout Itemize
-source code:
-\family typewriter
-libSnac/src/Stress.c
-\family default
- to exclude Syy from calculating the second invariants.
-
-\end_layout
-
-\end_deeper
-\begin_layout Itemize
The second invariant of stress in xz plane are monitored.
\end_layout
@@ -5673,12 +5662,6 @@
\end_layout
-\begin_layout Itemize
-Use this file to get the analytic solutions:
-\family typewriter
-thick_cylinder_tresca.py
-\end_layout
-
\begin_layout Standard
\noindent
\align center
@@ -5760,13 +5743,8 @@
\end_layout
\begin_layout Standard
-Problem Description: Expansion of a thick cylinder under uniform internal
- pressure.
- A constant and uniform internal pressure is applied to the inner surface
- of a thick cylinder without pre-stress.
- Taking advantage of symmetry, only a quadrant of the cylinder is modeled.
- The outer surface has zero confining pressure.
- Mohr-Coulomb yield criterion is used.
+The same problem with the previous section, but the Mohr-Coulomb yield criterion
+ is adopted here.
\end_layout
\begin_layout Subsection
@@ -5824,18 +5802,9 @@
\end_inset
31 nodes.
-
\end_layout
\begin_layout Itemize
-Use this file to reproduce this result: input file
-\family typewriter
-coulomb.xml
-\family default
-
-\end_layout
-
-\begin_layout Itemize
The second invariant of stress in xz plane are monitored.
\end_layout
@@ -5849,14 +5818,6 @@
\end_layout
-\begin_layout Itemize
-Use this file to get the analytic solutions:
-\family typewriter
-thick_cylinder_coulomb.py
-\family default
-
-\end_layout
-
\begin_layout Standard
\noindent
\align center
@@ -5882,7 +5843,7 @@
\begin_inset Caption
\begin_layout Standard
-Profile of the second invariant of stress along radial direction
+Profile of the second invariant of stress along radial direction.
\end_layout
\end_inset
@@ -5896,10 +5857,6 @@
\end_layout
\begin_layout Standard
-Relative errors for thick cylinder benchmark problem
-\end_layout
-
-\begin_layout Standard
\noindent
\align center
\begin_inset Float table
@@ -6178,7 +6135,7 @@
\begin_inset Caption
\begin_layout Standard
-Summary of Benchmarking Snac's Plastic Plugin
+Relative errors for thick cylinder benchmark problem II.
\end_layout
\end_inset
@@ -6196,14 +6153,8 @@
\end_layout
\begin_layout Standard
-A parallel-plate viscometer problem (
-\begin_inset LatexCommand cite
-key "Jaeger_1969"
-
-\end_inset
-
-) is simulated, in which viscoelastic material is squeezed between two parallel
- plates.
+A parallel-plate viscometer problem is simulated, in which viscoelastic
+ material is squeezed between two parallel plates.
The plates are moving at a constant velocity,
\begin_inset Formula $v_{0}$
\end_inset
@@ -6211,9 +6162,13 @@
.
Each plate has the length of 2L and is at a distance 2h from the other.
No slip is assumed between the material and the plates.
- The approximate analytical solution is given by Jaeger (1969, Elasticity,
- Fracture and Flow, 3rd Ed.
- New York: John Wiley & Sons, Inc.)
+ The approximate analytical solution is given by Jaeger
+\begin_inset LatexCommand cite
+key "Jaeger_1969"
+
+\end_inset
+
+.
\end_layout
\begin_layout Subsection
@@ -6268,38 +6223,9 @@
\begin_layout Itemize
Due to the assumption of the original problem setup, artificial forces should
be added to left and right surfaces.
-\end_layout
-
-\begin_layout Itemize
-Use these files to reproduce this result:
-\end_layout
-
-\begin_deeper
-\begin_layout Itemize
-input file:
-\family typewriter
-maxwell_bench.xml
-\family default
\end_layout
-\begin_layout Itemize
-Make sure insert this block of code into
-\family typewriter
-libSnac/src/Force.c
-\family default
-:
-\family typewriter
-maxwell_addforce.c
-\end_layout
-
-\begin_layout Itemize
-To visualize the results, use this visual program:
-\family typewriter
-maxwell_bench.net
-\end_layout
-
-\end_deeper
\begin_layout Standard
\noindent
\align center
@@ -6325,7 +6251,7 @@
\begin_inset Caption
\begin_layout Standard
-NEED CAPTION -- TODO
+The initial mesh (blue) with the velocity boundary condition (red arrows).
\end_layout
\end_inset
@@ -6345,32 +6271,18 @@
\begin_layout Standard
Color field represents stress.
Colored arrows for Snac's velocity; black arrows for analytic solution.
- Over the most part of the domain, two sets of arrows overlap.
+ Over the most part of the domain, two sets of arrows show good agreement.
\end_layout
\begin_layout Standard
-Relative error of velocity solution: ~ 5%.
- This might be acceptable because the analytic solution is only approximate.
- Still need to test further.
-
+The relative error of velocity solution is ~5%.
+ This might be acceptable because the analytic solution is only approximate
+ and for viscous fluid.
+ Therefore, refining the mesh does not help reduce the error.
\end_layout
-\begin_layout Quote
-Note: it turned out that the analytic solution given in Jaeger (1969) is
- for viscous fluid.
- Refining mesh won't help reduce the error.
-
-\end_layout
-
\begin_layout Standard
-Stress pattern looks consistent with the analytic solution.
- It is not easy to compare quantitatively, since SNAC prints out only the
- 2nd invariant of stress tensor that is averaged over one element.
- [Orig Manual Comment: TODO: Should all benchmarks be included?]
-\end_layout
-
-\begin_layout Standard
\noindent
\align center
\begin_inset Float figure
@@ -6395,7 +6307,9 @@
\begin_inset Caption
\begin_layout Standard
-NEED CAPTION -- TODO
+The second invariant of stress and velocities plotted on the deformed mesh.
+ Colored arrows for the Snac's solution and black ones for the analytic
+ solution.
\end_layout
\end_inset
@@ -6409,18 +6323,6 @@
\end_layout
\begin_layout Chapter
-Parameters
-\end_layout
-
-\begin_layout Standard
-No content was in the original manual
-\end_layout
-
-\begin_layout Standard
-
-\end_layout
-
-\begin_layout Chapter
\begin_inset LatexCommand label
name "cha:License"
@@ -7174,7 +7076,6 @@
Jaeger (1969), Elasticity, Fracture and Flow, 3rd Ed.
New York: John Wiley & Sons, Inc.
- -- TODO
\end_layout
\begin_layout Bibliography
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