When you apply an interaction or a prescribed condition to a region, you can display symbols in the viewport that represent the interaction or prescribed condition. By default, the symbols for interactions and prescribed conditions that use analytical field distributions are scaled based on the analytical field value. For symbols other than arrows, a plus sign (+) or a minus sign (–) is displayed inside each symbol to indicate whether the magnitude of the interaction or prescribed condition is positive or negative at that location. You can turn off the symbol scaling using the Attribute display options in the Assembly Display Options dialog box. For more information, see “Controlling the display of attributes,” Section 72.13.

Abaqus/CAE displays scaled-down symbols for interactions and prescribed conditions when an analytical field evaluates to zero for a portion of its region. These scaled-down symbols are noticeably smaller than the default symbol size. For more information, see “Understanding prescribed condition symbol type, color, and size,” Section 16.5.1.

The points used for symbol display on meshes coincide with the locations where the analytical field is evaluated during the analysis. On native geometry, when the symbols appear equally spaced along an edge or over the face of a model, Abaqus/CAE selects a random set of points to use for symbol display. The points selected for symbol display may or may not coincide with the locations where the analytical field is evaluated. In some cases the analytical field cannot be evaluated at a given point due to an error; for example, division by zero.

When this situation occurs, a message appears in the command line interface indicating that an error occurred while evaluating the analytical field. As a visual cue to indicate that there is an error, the symbols that are displayed in the viewport are no longer scaled, even though the setting to scale symbols based on the analytical field value is turned on. You can attempt to eliminate the evaluation error by changing the symbol density settings, which prompts Abaqus/CAE to select a different set of points to use for symbol display. For more information on changing the symbol density settings, see “Controlling the display of attributes,” Section 72.13.