Stress Tensor

This page discusses the results that are unique to the command, Results Inquire Inquire Other Results Stress Tensor.

Applicability: This command is available for all structural analyses and all element types that produce stress tensor results.

Note: For table contents, features, and options common to all of the Other Results commands, refer to the Other Results page.

Figure 1: Stress Tensor Diagram for a Finite Element

Stress Tensor Results

Attention: Tabulated stress tensor components follow the currently active coordinate system—Global, Element Local (for applicable element types), and user-defined (Rectangular, Cylindrical, or Spherical). However, the X, Y, and Z coordinates always remain based on the global coordinate system.

The following data columns and features are included in the table of Stress Tensor results:

Part Number and Element Number columns: A single node may be shared by more than one element and more than one part. A node has a unique set of stress tensor results for each element that shares it. The visibility of these two columns is conditional, as follows:
If the Smooth Results option is enabled, the nodal stresses of multiple elements are averaged into a single result per node, per part. In this case, the Element Number column is not displayed, but the Part Number column is. Each unique node is listed in one row per each part that shares the node.

If Smooth Results are enabled, and the Smooth across part boundaries option is also enabled, nodal stresses of multiple elements are averaged into a single result per node, even when the elements belong to more than one part. In this case, neither the Element Number nor the Part Number column is displayed. Each unique node is listed in only one row.

Notes:
An exception to the one node/one result rule (with smoothing enabled) is for plate, shell, or composite element results. For these types of elements, a single node has separate results for the top and bottom faces of the thickness the elements represent.

Tabulated stress tensor results follow some of the settings found under Results Contours Settings Plate/Shell Options. Specifically, the selection in the Two-Sided Display section determines whether both the top and bottom results are given at each node or only the top side or the bottom side result. The default display option is Both. The Reverse Sides in Plot sub-option does not affect the order of the nodal values in the Stress Tensor table. Similarly, the options in the Bending/Membrane section only affect the color contour plot. The Stress Tensor table always lists the total stress/strain, regardless of the selection in the Bending/Membrane section of the Plate Display Options dialog.

See the Results Smoothing section on this page for more information regarding the smoothing options.

Stress Tensors: The following six stress tensor results are listed in the table, one tensor component per column:
Stress Tensor XX

Stress Tensor YY

Stress Tensor ZZ

Stress Tensor XY

Stress Tensor YZ

Stress Tensor ZX

Notes:
All results are based on the current display units. The maximum (Max) and minimum (Min) values from each of the Stress Tensor columns are listed in the bottom two rows of the table, respectively.

For more information regarding stress tensors, see the Stress: Tensor subsection of the Linear Results page. Note that this information is also applicable to nonlinear analyses.

For composite elements, the tabulated stress tensor values are consistent with the contour plot results shown using the following settings in the Composite Options dialog (Results Contours Stress Composites Options):
Lamina = Worst Results

Strain Calculation = Total Strain

The Stress Tensor tabulation does not respond to changes made in the Composite Options dialog. These settings only affect the color contour plot.

Stresses at each individual lamina of composites are not tabulated in the Stress Tensor table. You must view results for individual laminae via the color contour plot. Activate the Results for specific Lamina option in the Composite Options dialog to do so. The values given in the Stress Tensor table are for the top and bottom faces of the total composite stack that the elements represent.

For more information regarding composite element results, see the Composite section of the Linear Results page. Note that this information is also applicable to nonlinear analyses.

Results Smoothing

Smoothing settings are located along the bottom of the Stress Tensor table window, consisting of a checkbox and a button, as detailed below:

Smooth Results:

When the Smooth Results option is activated, results of multiple elements at each node are combined according to the currently specified smoothing options. As explained previously, this option affects the visibility of the Element Number column of the Stress Tensor table.

Smoothing Options:

Click the Smooth Options button to access the Smoothing Options dialog. The following settings are located in this dialog:

Smoothing function: Choose the desired smoothing method from this drop-down menu. The choices are as follows:
None: No smoothing (equivalent to deactivating the Smooth Options checkbox.

Maximum: Display the maximum (that is, the most positive) value among the elements sharing the node.

Maximum Magnitude: Display the value with the greatest magnitude (whether positive or negative) from among the elements sharing the node.

Mean: This is the default setting. Results from the elements sharing each node are averaged and the mean value is displayed.

Minimum: Display the minimum (that is, the most negative) value among the elements sharing the node.

Range: Display the difference between the maximum and minimum values among the elements sharing the node.

Sum: Display the sum of all values from each element sharing the node.

Smooth across part boundaries: By default, smoothing is not performed across part boundaries (option disabled). Different parts might be comprised of different materials, each with a unique stiffness. Therefore, the relationship between strain and stress vary, and the stresses should be separately calculated for each part. If the parts are bonded and the materials have similar stress-strain behavior, it may be appropriate to smooth the results across the part boundaries. In such cases, activate the Smooth across part boundaries option to combine the results from all elements into a single value at each node where two or more parts meet.

As explained previously, this option affects the visibility of the Part Number column.