4.6. Reviewing Results

The program writes results from a transient analysis to the magnetic results file, Jobname.rmg. Results include the data listed below:

Primary data: Nodal DOFs (AZ, CURR, EMF, MAG, VOLT)

Derived data:

  • Nodal magnetic flux density (BX, BY, BSUM)

  • Nodal magnetic field intensity (HX, HY, HSUM)

  • Nodal magnetic forces (FMAG: components X, Y, SUM)

  • Nodal reaction current segments (CSGZ)

  • Total electric current density (JT)

  • Joule heat per unit volume (JHEAT)

Additional data, specific to each element type, also is available. See the Element Reference for details.

You can review analysis results in POST1, the general postprocessor, or in POST26, the time-history postprocessor:

  • POST26 enables you to review results at specific points in the model over the entire transient.

  • POST1 enables you to review results over the entire model at specific time points.

To choose a postprocessor, choose one of the following:

Command(s): /POST1 or /POST26
GUI: Main Menu> General Postproc
Main Menu> TimeHist Postpro

2D Harmonic Magnetic (AC) Analysis and 3D Harmonic Magnetic Analysis (Edge-Based) of this manual discuss Mechanical APDL commands that you may find useful in examining analysis results.

4.6.1. Reading Results in POST26

To review results in POST26, the time-history postprocessor, the database must contain the same model for which the solution was calculated, and the Jobname.rmg file (the results file) must be available. If the model is not in the database, restore it using the command or menu path listed below and then use the SET command or its equivalent menu path to read in the desired set of results.

Command(s): RESUME
GUI: Utility Menu> File> Resume Jobname.db

POST26 works with tables of result item versus time, known as variables. Each variable is assigned a reference number, with variable number 1 reserved for time. Therefore the first things you need to do is define the variables.

To define primary data variables, use either of the following:

Command(s): NSOL
GUI: Main Menu> TimeHist Postpro> Define Variables

To define derived data variables, use either of the following:

Command(s): ESOL
GUI: Main Menu> TimeHist Postpro> Define Variables

To define reaction data variable, use either of the following:

Command(s): RFORCE
GUI: Main Menu> TimeHist Postpro> Define Variables

Once you have defined these variables, you can graph them (versus time or any variable). To do so, use this command or menu path:

Command(s): PLVAR
GUI: Main Menu> TimeHist Postpro> Graph Variables

To list the variables, use this command or menu path:

Command(s): PRVAR
GUI: Main Menu> TimeHist Postpro> List Variables

To list only the extreme variable values, use this command or menu path:

Command(s): EXTREM
GUI: Main Menu> TimeHist Postpro> List Extremes

By reviewing the time-history results at strategic points throughout the model, you can identify the critical time points for further POST1 postprocessing.

To calculate and summarize electromagnetic forces, power loss, energy, and current on element components (created in the PREP7 preprocessor via the CM command (Utility Menu> Select> Comp/Assembly> Create Comp/Assembly)), you can use either of the following:

Command(s): PMGTRAN
GUI: Main Menu> TimeHist Postpro> Elec&Mag> Magnetics

POST26 offers many other functions, such as performing math operations among variables, moving variables into array parameters, etc. For more information, see the Basic Analysis Guide.

4.6.2. Reading Results in POST1

To review results in POST1, the database must contain the same model for which the solution was calculated. Also, the results file (Jobname.rmg, or Jobname.rst if either the magnetic scalar potential or electric potential DOFs are active) must be available.

To read results at the desired time point into the database, use either of the following:

Command(s): SET,,,,,TIME
GUI: Utility Menu> List> Results> Load Step Summary

If you specify a time value for which no results are available, the program performs linear interpolation to calculate the results at that time. The program uses the last time point if the time specified is beyond the time span of the transient analysis. You can also identify the results to be read by their load step and substep numbers.

You can display contours of potentials (AZ, VOLT) flux density (BX, BY) and field intensity (HX, HY) using either of the following methods:

Command(s): PLESOL, PLNSOL
GUI: Main Menu> General Postproc> Plot Results> Contour Plot> Element Solution
Main Menu> General Postproc> Plot Results> Contour Plot> Nodal Solu

You can display vector (arrow) displays of vector quantities such as A, B, and H using either of the following methods:

Command(s): PLVECT
GUI: Main Menu> General Postproc> Plot Results> Vector Plot> Predefined
Main Menu> General Postproc> Plot Results> Vector Plot> User Defined

4.6.2.1. Coil Resistance and Inductance

For stranded coils with the voltage-fed or circuit-fed options, you can calculate the resistance and inductance of the coil. Each element stores values of resistance and inductance. Summing these values gives the total resistance and inductance of the modeled region of the conductor. To store and sum these values, select the conductor elements using the ETABLE,tablename,NMISC,n command or its equivalent menu path. (For the n value, use 8 for resistance and 9 for inductance.) Use the SSUM command or its menu path equivalent to sum the data.

4.6.2.2. Calculating Other Items of Interest

You can calculate many other items of interest (such as flux lines, eddy currents, torque, and force) from the data available in the database in postprocessing. The Mechanical APDL command set supplies the following macros for these calculations:

  • The CURR2D macro calculates current flow in a 2D conductor.

  • The EMAGERR macro calculates the relative error in an electrostatic or electromagnetic field analysis.

  • The FLUXV macrocalculates the flux passing through a closed contour.

  • The MMF macro calculates magnetomotive force along a path.

  • The PLF2D macro generates a contour line plot of equipotentials.

  • The SENERGY macro determines the stored magnetic energy or co-energy.

For more discussion of these macros, see Electric and Magnetic Macros.

For information on the macros applicable to PLANE233, see the element's description in the Element Reference.