Patch Test Error, Dirichelet Boundary Conditions not working

[PeterWoerner]

When I run the patch test from example 1, in particular, it seems that the Dirichlet conditions in the y direction aren't working and that the strains in the x-direction are significantly larger than expected.

Thanks in advance for the help.

[Prof. R.L. Taylor]

There seems to be something wrong with your code.  If you look at the output file you will see the solver had trouble and then the resulting displacements are from a singular matrix.

[PeterWoerner]

Dr. Taylor,

Do you mean in the input file or in the Fortran code?  There were a ton of warnings during the installation.

Peter

[Prof. S. Govindjee]

A couple of comments:

1. You are running a very old version of FEAP 8.3 alpha.  You should upgrade to the newest version 8.5.  The compiler warnings are appearing due to stricter compiler standards.  Version 8.5 addresses these issues (though 8.3 should still run file, you may want to turn off the compiler warnings).

2. There is something very wrong with your version of the code.  It is showing 17 equations when there should only be 14 (9 nodes * 2 eq/node - 4 boundary conditions).  You should download a clean version of the source and re-install.

3.  Attached is an output file generated from your Ipatch_4el.  You can use it to check if your code is working correctly.

[Prof. S. Govindjee]

fyi, I found a version of 8.3 and it ran just fine on your problem.  It was VERSION: Release 8.3.19 DATE: 29 March 2011, which is the last released 8.3 version.     

[PeterWoerner]

Dr. Govindjee,

Thanks so much for the help.  I will talk with my advisor about getting a clean version/updating.

Peter