Mechanical APDL Basic Analysis Guide - Ansys

Chapter 7:The General Postprocessor (POST1)
This method is not normally used, but can be useful in special circumstances. Averaging operations should
not be done at nodal interfaces of differing materials.
• Vector sum data: These follow the same practice as the principal stresses. By default, the vector sum
magnitude (square root of the sum of the squares) at each node is calculated from averaged components.
By using the AVPRIN command, you can reverse this, so that the vector sum magnitudes are first calculated
per element, then averaged at the nodes.
• Shell elements or layered shell elements: By default, results for shell or layered elements are assumed to
be at the top surface of the shell or layer. To display results at the top, middle or bottom surface, use
the SHELL command (Main Menu> General Postproc> Options for Outp). For layered elements, use
the LAYER command (Main Menu> General Postproc> Options for Outp) to indicate layer number.
• von Mises equivalent strains (EQV): The effective Poisson's ratio used in computing these quantities may
be changed using the AVPRIN command.
Command(s): AVPRIN
GUI: Main Menu> General Postproc> Plot Results> Contour Plot> Nodal Solu
Main Menu> General Postproc> Plot Results> Contour Plot> Element Solu
Utility Menu> Plot> Results> Contour Plot> Elem Solution
Typically, you would set the effective Poisson's ratio to the input Poisson's ratio for elastic equivalent
strain (item and component EPEL,EQV) and to 0.5 for inelastic strains (item and component EPPL,EQV
or EPCR,EQV). For total strains (item and component EPTOT,EQV), you would typically use an effective
Poisson's ratio between the input Poisson's ratio and 0.5. As an alternative, you can save the equivalent
elastic strains using ETABLE with the effective Poisson's ratio equal to the input Poisson's ratio and save
the equivalent plastic strains in another table using 0.5 as the effective Poisson's ratio, then combine
the two table entries using SADD to obtain the total equivalent strain.
• Effect of /EFACET: You may see different plots with different /EFACET settings when viewing continuous
contour plots (PLNSOL). If you set /EFACET,1, the contour values for the intermediate locations are interpolated
based on the average of the adjacent averaged corner node values. However, if you set
/EFACET,2, the midside node values are first calculated within each element, based on the average of
the adjacent unaveraged corner node values. The midside node values are then averaged together for
a PLNSOL contour plot. If you issue /EFACET,4, the program uses shape functions to calculate results
values at three subgrid points along each element edge. The subgrid values are first calculated within
each element and are then averaged together for PLNSOL plots. Therefore, the contour values at the
midside locations will differ with different /EFACET settings.
In most cases, PLESOL contours will be the same regardless of /EFACET settings. However, you will see
differences in PLESOL contour plots if you change /EFACET settings in conjunction with any RSYS
setting other than KCN = 0. When a coordinate system other than global Cartesian is chosen (KCN = 1,
2, etc.), the results are first averaged in the global Cartesian coordinate system, and then the averaged
results are transformed to the specified results coordinate system.
7.2.1.2. Deformed Shape Displays
You can use these in a structural analysis to see how the structure has deformed under the applied loads.
To generate a deformed shape display, use one of the following:
Command(s): PLDISP
GUI: Utility Menu> Plot> Results> Deformed Shape
Main Menu> General Postproc> Plot Results> Deformed Shape
For example, you might issue the following PLDISP command:
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