To specify the analysis type, do either of the following:

If you want to restart a previous analysis (for example, to restart an unconverged solution or to specify additional excitation), issue the command ANTYPE,HARMIC,REST. You can restart an analysis only if you previously completed a harmonic magnetic analysis, and the files Jobname.EMAT, Jobname.ESAV, and Jobname.DB from the previous run are available.

Most 2-D nonlinear harmonic problems run at a single frequency can be set up and solved using either of the following:

Details on the HMAGSOLV macro are described in HMAGSOLV Command Macro. Defining Analysis Options through Starting the Solution describe the analysis options that can be used if the HMAGSOLV macro is not used. HMAGSOLV is only applicable to a new harmonic analysis.

You can use the following "Full" method to solve harmonic electromagnetic problems. It is the default method.

First, define the solution method, using either of the following:

Next, define how the harmonic degree of freedom solution is listed in the printed output (the Jobname.OUT file). You can choose either real and imaginary parts (default) or amplitudes and phase angles. This option is used mainly with circuit-coupled problems using the CURR and EMF degrees of freedom. To specify the solution listing format, use either of the following:

You can choose the sparse direct (SPARSE) solver (default), the frontal solver, the Jacobi Conjugate Gradient (JCG) solver, or the Incomplete Cholesky Conjugate Gradient (ICCG) solver.

To select an equation solver, use either of the following:

For nonlinear problems, the program continues to do equilibrium iterations until the convergence criteria are satisfied (or until the maximum number of equilibrium equations is reached.

To specify the convergence criteria, use either of the following:

You can either use the default convergence criteria or define custom criteria.

For most electromagnetic problems only a single frequency is used. You set the frequency (in Hz), using either of the following:

You can input a single frequency in either the FREQB or FREQE field.

You can specify the number of harmonic solutions to be calculated. The solutions (or substeps) is evenly spaced within the specified frequency range. For example, if you specify 10 solutions in the range 30 to 40 Hz, the program calculates the response at 31, 32, 33, ..., 39, and 40 Hz. No response is calculated at the lower end of the frequency range.

To specify the number of harmonic solutions, use either of the following:

You can specify whether the excitations are stepped or ramped. By default, they are ramped, that is, excitation amplitude is gradually increased with each substep. By stepping the excitations, the same excitation amplitude is maintained for all substeps in the frequency range. For electromagnetic problems excitations are normally stepped. The ramp option is useful for converging nonlinear problems at a single frequency.

To specify whether the excitations are stepped or ramped, use either of the following:

You can specify the number of equilibrium iterations performed for a nonlinear harmonic analysis at each frequency. The default is 25. It is recommended that the number of equilibrium iterations be set to 50 or higher to ensure convergence.

To specify the number of equilibrium iterations, use either of the following:

You can set output control options.

An option enables you to include any results data in the printed output file (Jobname.OUT). To control printed output, use either of the following:

Another option controls what data goes to the results file (Jobname.RTH). To control database and results file output, use either of the following:

Use the SAVE_DB button on the ANSYS Toolbar to save a backup copy of the ANSYS database. To retrieve a model, re-enter ANSYS and use one of the following:

For linear problems you can initiate a solution using either of the following:

For a nonlinear analysis, a two-step solution sequence at each frequency is recommended to ensure convergence:

Instead of specifying the two-step solution sequence and initiating the solution manually using the analysis options documented above, you can take advantage of the HMAGSOLV command macro. To do so, use either of the following:

The HMAGSOLV command macro allows for changing the default convergence criteria for each valid degree of freedom. Due to the nature of the nonlinear harmonic equation set, convergence is slower than it is for a static analysis. The default values should provide adequate solution accuracy.

As nonlinear electromagnetic analysis proceeds, ANSYS computes convergence norms with corresponding convergence criteria each equilibrium iteration. Available in both batch and interactive sessions, the Graphical Solution Tracking (GST) feature displays the computed convergence norms and criteria while the solution is in process. By default, /GST is ON for interactive sessions and OFF for batch runs. To turn /GST on or off, use either of the following:

Figure 3.5: "Convergence Norms Displayed by the Graphical Solution Tracking (GST) Feature" shows a typical GST display:

To leave the SOLUTION processor, use either of the following: