Restarted jobs with proportional load data

[Colin McAuliffe]

Hi all,

I am having some trouble with restarted jobs in both serial and parallel. As a test I ran restarted jobs for example 8 from the feap example manual. All of the files were too big to attach, but I attached the input files for serial.


From the output file I get for the serial run, it looks like the proportional loads after the restart are not correct compared to the original run with no restart. For the parallel run, after restart the job fails due to the residual norm being inf or nan. Any idea what the cause might be?

All the best,
Colin

[Prof. R.L. Taylor]

Colin,

In the serial version of feap you need to set the name of the restart file you will read from.  If you check the output you will find that it did not find the default file RserialR.

Secondly, you need to include the load level you are starting from at the new time.  The easiest way in your file is to include the same proportional loading data.

Parallel restart may need some further testing, but you should look to see what files are created (Rserial001 in the serial version).  There should be restart files for every processor --   If you set the one for processor 1 the others should sequence as per other files.

[Colin McAuliffe]

Thanks for the reply Prof. Taylor. Including the same prop load data fixed the issue with the missing load sor serial, and it works now. For the parallel (one processor) simply using the REST command without specifying a file seems to read in the data properly, but the result is still the residual norm nan or inf. The output is below:

 feap * * Domain 1 Nodes in partition=992                                     

     Solution Commands       Variable 1  Variable 2  Variable 3
       PROP                  0.0000E+00  0.0000E+00  0.0000E+00
       DT                    1.0000E-01  0.0000E+00  0.0000E+00
 *Command   1 * prop                v:   0.00       0.00       0.00   
                                                           t=     0.26     0.01
                              Proportional Load Table Number  1
 *Command   2 * dt                  v:  0.100       0.00       0.00   
                                                           t=     0.26     0.01
 *End of Solution Execution*                               t=     0.26     0.01

 feap * * Domain 1 Nodes in partition=992                                     

     Solution Commands       Variable 1  Variable 2  Variable 3
       PETSc     ON          0.0000E+00  0.0000E+00  0.0000E+00
       REST                  0.0000E+00  0.0000E+00  0.0000E+00
       LOOP                  1.0000E+01  0.0000E+00  0.0000E+00
       TIME                  0.0000E+00  0.0000E+00  0.0000E+00
       LOOP                  3.0000E+01  0.0000E+00  0.0000E+00
       TANG                  1.0000E+00  0.0000E+00  0.0000E+00
       NEXT                  0.0000E+00  0.0000E+00  0.0000E+00
       NEXT                  0.0000E+00  0.0000E+00  0.0000E+00
 *Command   1 * pets ON             v:   0.00       0.00       0.00   
                                                           t=     0.26     0.01
  PETSC Solver

 *Command   2 * rest                v:   0.00       0.00       0.00   
                                                           t=     0.26     0.01
   Restart from : RParallel_0001                                                                                                                     
   R e s t a r t   I n p u t   D a t a
          Time step number  =      10
          Time at restart   = 1.00000E+00
          Time increment    = 1.00000E-01
          Displacements input
          Proportional load = 1.00000E+00
          Arc-length   load = 1.00000E+00
          Force vector input
          Prop load data input
          History data input
 *Command   3 * loop                v:   10.0       9.00       0.00   
                                                           t=     0.26     0.01
 *Command   4 * time                v:   0.00       0.00       0.00   
                                                           t=     0.26     0.01

   Computing solution at time  1.1000E+00: Total proportional load  9.0000E-01
 *Command   5 * loop                v:   30.0       8.00       0.00   
                                                           t=     0.27     0.01
 *Command   6 * tang                v:   1.00       0.00       0.00   
                                                           t=     0.27     0.01
  *ERROR* Residual norm is NaN or Inf

On the other hand if after the REST command I use
FORM
OUTP,FORM
the result is fine.