On Tue, Oct 30, 2012 at 11:15 AM, Scott Henderson <span dir="ltr"><<a href="mailto:sth54@cornell.edu" target="_blank">sth54@cornell.edu</a>></span> wrote:<br><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div style="word-wrap:break-word"><div>Here is an output log with all the flags on. I'm thinking maybe the problem is not sufficiently constrained by the boundary conditions I've applied here...</div></div></blockquote>
<div><br></div><div>There are all sorts of improvements that can be made to this solver, but lets defer that until</div><div>the modeling is cleared up. Since this problem is so small, just crank up the linear solver to</div>
<div>get exact results:</div><div><br></div><div> --petsc.ksp_rtol=1.0e-10</div><div><br></div><div>However, it appears to be making no progress at all after the Newton solve, so as you say, its</div><div>likely to be something with the problem setup. Brad is the best at diagnosing friction problems.</div>
<div><br></div><div> Matt</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div style="word-wrap:break-word"><div><div>On Oct 30, 2012, at 11:03 AM, Matthew Knepley <<a href="mailto:knepley@mcs.anl.gov" target="_blank">knepley@mcs.anl.gov</a>> wrote:</div>
<br><blockquote type="cite">On Mon, Oct 29, 2012 at 11:25 AM, Scott Henderson <span dir="ltr"><<a href="mailto:scottyhq@gmail.com" target="_blank">scottyhq@gmail.com</a>></span> wrote:<br><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Hello CIG-users,<br>
<br>
I've been trying to use Pylith for a "single edge notch in tension (SENT)" fracture mechanics simulation. In order to do this I've modified step20.cfg to be a 2D plane-stress problem. I've also followed what I could from this mailing-list post (<a href="http://www.geodynamics.org/pipermail/cig-short/2012-September/001120.html" target="_blank">http://www.geodynamics.org/pipermail/cig-short/2012-September/001120.html</a>). I'm still not able to get expected results, which makes me think I' doing something incorrectly with the pylith settings (PETSC in particular). I'm pretty new to the software, so any tips on the cubit mesh or pylith cfg files would be appreciated (zipped folder attached).<br>
<br>
Essentially, I'm not getting the expected u2 displacements from this analysis (but they are not unreasonable), and the following SNES output makes me concerned:<br>
<br>
500 SNES Function norm 2.483466683115e-06<br>
Nonlinear solve did not converge due to DIVERGED_MAX_IT iterations 500<br>
<br>
Increasing snes_max_it doesn't seem to lead to convergence.<br></blockquote><div><br></div><div>Always send all output. The nonlinear solver is not converging, but the first thing to check is</div><div>how the linear solver is doing inside. Also, I want to see exactly what solver setup you have.</div>
<div><br></div><div> Matt</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Any suggestions appreciated,<br>
Scott<br>
<br>
<br>
<br>
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<br></blockquote></div><br><br clear="all"><div><br></div>-- <br>What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br>
-- Norbert Wiener<br>
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</blockquote></div><br></div><br></blockquote></div><br><br clear="all"><div><br></div>-- <br>What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br>
-- Norbert Wiener<br>