You can use the Section Points dialog box to control the section points from which ABAQUS obtains integration point results and material orientations. Reinforcement (rebar) layers in membrane, shell, and surface elements are treated as section points for output purposes; each reinforcement layer has a unique name. For example, you can request results from the section points at the top surfaces of certain shells in the model, from the middle section points of certain beams in the model, or from a named reinforcement layer in certain membrane elements in the model.

The Section Points dialog box is shown in Figure 24–2.

The Category field at the top of the dialog box displays a list of element categories. The elements within each category share common section properties, such as those listed below:

The label for each category includes information about the section properties of the elements within the category. For example, the first category label that appears in the Category list in Figure 24–2 indicates the following:

The Bottom Location and Top Location fields display the two section points at which you can currently display output for the selected category. By default, these fields display the SNEG and SPOS section points, respectively; however, you can change either location if you want to display output at a different section point. A list of available section points for the selected category is available in the Available Section Points in Cross-section field at the bottom of the dialog box.

ABAQUS/CAE displays output only at active locations. You can control the active status of the two section point locations by using the Active locations radio buttons at the top of the dialog box. Select Bottom or Top to activate only the Bottom Location or Top Location section point. For contour plots of integration point variables on three-dimensional shells, select Top and bottom to display output simultaneously at both section points. Only contour plots of this type can display output for both section points simultaneously; in all other contexts, ABAQUS/CAE displays output only at the Bottom Location section point when you select Top and bottom.

Contour plots displaying output at two section points vary in appearance depending on the type of shell. In a conventional shell the two contours appear as a double-sided shell with different contours on each side, while in a continuum shell the two contours appear as distinct two-dimensional contour fronts at each section point location. Axisymmetric shells, which are composed of line elements swept to form a three-dimensional surface, exhibit neither behavior because they are not considered three-dimensional shells; instead, these shells display output at a single section point only.

In many cases the location of a section point is described in terms of its position relative to the midpoint of the cross-section. For two-dimensional beams this relative position is reported as a fraction of the distance between the midpoint of the cross-section and the top or bottom surface of the section. For shells this relative position is reported as a fraction of the distance between the midpoint of the cross-section and the SPOS or SNEG surface of the section. Reinforcement layers are indicated by their unique name.

For example, in Figure 24–2 the selected category contains a shell section with five section points. Therefore, the Available Section Points in Cross-section field contains a list of the five section point locations. The section point in the middle of the section is Mid, fraction = 0.0; the section point between the middle of the section and the SPOS surface is fraction = 0.5; the section point between the middle of the section and the SNEG surface is fraction = -0.5; and so on.

For beams with three-dimensional sections, the relative position of a section point can be reported as a fraction of the distance between the midpoint of the cross-section and

For example, Figure 24–3 shows the section point locations in a three-dimensional L-section beam.In other cases, angles are used to indicate section point locations. For example, Figure 24–4 shows the section point locations in a three-dimensional pipe section.Figure 24–5 shows the section point locations in a three-dimensional circular beam section, reported as a fraction of the circle's radius.

For more information about where section points are located in different section types, see the following:

For more information about reinforcement layers, see “Defining reinforcement,” Section 2.2.3 of the ABAQUS Analysis User's Manual.

For information on related topics, click the following item: