The program writes the results from a transient thermal analysis to the thermal results file, Jobname.rth. Results contain the following data (all of which are functions of time):
Primary data
Nodal temperatures (TEMP)
Derived data
Nodal and element thermal fluxes (TFX, TFY, TFZ, TFSUM)
Nodal and element thermal gradients (TGX, TGY, TGZ, TGSUM)
Element heat flow rates
Nodal reaction heat flow rates
...etc.
You can review these results using either of the following:
The general postprocessor, POST1. It lets you review results at one time step over the entire model or a selected part of the model.
The time history postprocessor, POST26. It lets you review results at specific points in the model over all time steps. Other POST26 capabilities include graph plots of results of data versus time or frequency, arithmetic calculations, and complex algebra.
The next few paragraphs describe some typical postprocessing operations for a transient thermal analysis. For a complete description of all postprocessing functions, see the Basic Analysis Guide.
Note: To review results in either postprocessor, the database must contain the same model for which the solution was calculated. (If necessary, retrieve the model.) In addition, the results file, Jobname.rth, must be available.
After you enter POST1, use the SET command to read in results at the desired time point.
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 you specify a time that is beyond the time span of the transient.
You also can have the program read results by their load step and substep numbers. To do so, use the following menu path: .
Caution: For a nonlinear analysis, linear interpolation of results data between time points can cause some loss of temporal accuracy. Therefore, take care to specify a time value for which a solution is available.
The time history postprocessor, POST26, works with tables of result items versus time, known as variables. The program assigns each variable a reference number, with variable number 1 reserved for time.
If you are reviewing your analysis results using POST26, begin by defining the variables.
To define variables for primary data, use the NSOL command.
To define variables for derived data, use the ESOL command.
To define variables for reaction data, use the RFORCE command.
Once your variables are defined, you can convert them to a graph, issue the PLVAR command. This command also gives you a listing of the variables.
To list only the extreme variable values, use the EXTREM command.
By reviewing the time-history results at strategic points throughout the model, you can identify the critical time points for further postprocessing with POST1.
POST26 offers many other functions including performing arithmetic operations among variables, moving variables into array parameters, and moving array parameters into variables. For details, see Basic Analysis Guide.