Controlling result averaging

You can control the averaging of element-based field output results, such as stress or strain. Averaging is applicable to creating line- and banded-type contours, probing nodal locations, forming display groups and color coding based on result values, or extracting X–Y data along a path.

Related Topics
Understanding result value averaging

Context:

Element values are first extrapolated to the nodes. Nodes common to two or more elements will receive multiple contributions. To control the averaging of multiple contributions, you can:

  • Enable or suppress averaging.

  • Define result regions and choose whether averaging will cross them.

  • Include or exclude shell and membrane feature edges as additional region boundaries for averaging.

  • Suppress averaging of elements that are not displayed.

  • Choose whether Abaqus/CAE computes invariants before or after averaging.

  • Set the averaging threshold.

The averaging threshold governs the extent of averaging; it is available when Abaqus/CAE computes invariants or extracts components before averaging. If the relative difference between contributions at a node is greater than the threshold percentage you set, Abaqus/CAE will not average the contributing values and your results will appear discontinuous at that node. Use a higher percentage to produce a smoother, more continuous effect.

For information on averaging across regions, see Controlling computations at region boundaries.

  1. Locate the Averaging options.

    From the main menu bar, select ResultOptions; then click the Computation tab in the dialog box that appears. The Averaging options appear.

  2. To control whether Abaqus/CAE averages output from multiple elements at shared nodes, toggle Average element output at nodes.

    Suppress averaging to identify discontinuities in the field output or to establish contour limits based on the extrapolated, unaveraged results.

  3. Toggle off Use region boundaries to ignore region boundaries and average results across the entire model.

  4. If region boundaries are used, specify the result regions to set the boundaries. For more information, see Controlling computations at region boundaries.

    Tip: To view the current result regions, color code an undeformed or deformed plot using the Averaging regions method of attribute selection. (For more information, see Coloring all geometry in the Visualization module.)

  5. If region boundaries are used, by default Abaqus/CAE includes shell and membrane feature edges as additional region boundaries. To change the minimum angle used to create feature edges, click and change the Feature Angle setting in the ODB Display Options dialog box. Feature edges correspond to the undeformed model and are not recalculated for model deformation. (For more information, see Defining model feature edges.)

    To average the results across feature edges, toggle off Include shell/membrane feature edge boundaries.

  6. To control whether Abaqus/CAE averages nodal results based on all contributing elements or based only on the elements in the current display group, toggle Average only displayed elements.

  7. Choose whether Abaqus will compute invariants (scalars) and extract components before or after averaging results over the specified regions.

    By default, Abaqus computes the scalars before averaging; if you choose to compute the results after averaging, Abaqus averages all results and their orientations to maintain a valid basis for computing the invariants.

    Tip: To view the nodal-averaged orientations in a contour plot, you can display their labels using the Contour Plot Options dialog box. For more information, see Displaying nodal-averaged orientations.

  8. If you compute scalars before averaging, you can set the Averaging Threshold (%) to control the averaging between neighboring elements. A value of 0 suppresses all averaging; a value of 100 averages all results.

  9. Click Apply to implement your changes.

    Abaqus averages result values for the display in the current viewport according to your specifications. The contour legend, if active, changes to state the averaging threshold that you have specified. For more information on the contour legend, see Customizing the legend.

    By default, your changes are saved for the duration of the session and will affect all subsequent display of results. If you want to retain your changes for subsequent sessions, save them to a file. For more information, see Saving customizations for use in subsequent sessions.