Create the Fatigue Step

To perform a progressive fatigue analysis, an additional fatigue step is required.

This step will be created by modifying the input file.

1. First we fully specify the bounds of the mechanical loading step from above by adding two commands.
2. Locate the TREF, 297.15 command.
3. Below this enter /SOLU, so that the input file now appears as seen below:

   TREF,297.15,
   /SOLU
   FLST,2,104,1,ORDE,4

4. Now we add a command to end this loading step.
5. Locate the OUTRES,ESOL,ALL command.
6. Below this enter SOLVE to end the step.

Now that the mechanical loading step has been defined, we add the fatigue step.

7. Below the SOLVE command from step 6 above, enter the following to define the fatigue step:

   /SOLU
   TIME, 1
   NSUBST, 100, 100, 100
   NEQIT, 1000
   NROPT,FULL,,OFF 
   PRED,OFF,,OFF
   OUTRES, SVAR, ALL  
   OUTRES, NSOL, ALL
   OUTRES, ESOL, ALL
   SOLVE
   FINISH

This step will have 100 increments over a time period of 1 second. All of the state variables as well as the element and node solutions will be written to the results file.