Discontinuities and discontinuity printout

discontinuities

Discontinuities printout

You can cure aliasing by reducing the print interval but alternatively you can sometimes cure it by enabling Discontinuity printout:

Procedure

1. Display the Run parameters dialog box.

2. Select the Standard options tab.

3. Tick the Discontinuities printout box in the Dynamic run options area.

Figure 105: Standard options

Results

In very simple language a discontinuity is an event that is physically and/or numerically rather violent. In the current system, the discontinuity occurs many times when the angle reaches 360° and then immediately drops back to 0°.

The option Discontinuities printout gives extra data in the results file. At the expense of a bigger results file you get a sharper graph. See the following figure.

When your simulation runs, a results file is created. For the present system, this is called RotaryInertia_.results. By extra printout, we really mean extra data is added to this file just before and just after each discontinuity. In some examples, this is price well worth paying but for some systems that have large numbers of discontinuities, the results file would be too big.

Figure 106: New output of the modulo block of system A

Finally do a run with Stabilizing and Dynamic mode enabled. Note how the initial transient is successfully removed.