Interactive program operation

In interactive mode, the program is started (usually specifying an input file and possibly additional parameters as explained under Command-line parameters.

Non linear Finite Element calculation

In the first phase, the program loads the data file and performs all Finite Element calculations. During which the program displays progress information in the format:

    STEP    2    Error =  0.450

Note that the Error indicated above indicates the level of accuracy reached by the solution. If the solution has fully converged, the remaining error is approximately zero. An error as large as that shown would be unacceptable for the last iteration of the calculation.

The user specifies the number of iterations to be performed in the input file, or overrides that value using the -iterations command-line parameter. Typical number of iterations for a good solution is between 20 and 50, but can be as high as 200 or more. If the error in the last iteration remains large, it is likely that the applied load is too large for the structure.