Mechanical APDL Basic Analysis Guide - Ansys

Chapter 7:The General Postprocessor (POST1)
• TORQSUM (Main Menu> General Postproc> Elec & Mag Calc> Component Based> Torque) summarizes
electromagnetic Maxwell and Virtual work torque calculations on element components for 2-D
planar problems.
See "Electric and Magnetic Macros" in the Low-Frequency Electromagnetic Analysis Guide for more information
on ANSYS magnetic command macros.
7.4.8. Comparing Nodal Solutions From Two Models (RSTMAC)
In a typical design procedure, you may want to make small changes to your model and compare the solutions
you obtain from the new model to solutions from the original model.
The RSTMAC command compares the nodal solutions from the results files (*.RST) of two such analyses.
Only structural degrees of freedom are considered, and nodal solutions (real or complex) from any analysis
type are supported. The procedure is based on the Modal Assurance Criterion (MAC) calculations (see POST1
- Modal Assurance Criterion (MAC) for more details.
Because the two results files may correspond to different models and/or meshes, the first step consists of
either:
• Matching the nodes of model 1 and model 2. This is the default procedure. It is recommended when
meshes are identical or very similar.
Or
• Mapping the nodes of model 2 into elements of model 1. This procedure is activated with TolerN =
-1 on the RSTMAC command. In this case, the solutions of model 1 are interpolated. It is the most
general procedure but it is generally more time consuming.
Note
If you want to compare the nodal solutions of cyclic symmetric sectors, use the mapping and interpolation
method (TolerN = -1). Because the nodes of the basic sector and the nodes of the
duplicate sector are coincident, the node mapping is done separately for each sector. Model 1
and model 2 must have the same number of sectors.
The next two steps consist of:
• Performing the MAC calculations.
• Identifying the best solution matches.
Note
The modes obtained after a modal analysis of a cyclic symmetric structure are repeated when
the harmonic index is greater than zero. In this case, the MAC values table is compressed to allow
the solutions matching. This compression consists of summing and averaging the MAC values of
the repeated frequencies.
All 3 of these steps are detailed below using 2 models of a simply supported beam. Model 1, tsolid, is a
solid element mesh. Model 2, tbeam, is a beam element mesh.
All of the first 10 eigensolutions are compared, and a full printout is requested (KeyPrint=2 on the RSTMAC
command).
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