Form: Section Cuts, Section Cut Data
Use the Define menu > Section Cuts command to obtain resultant forces acting at section cuts through a model. Section cuts can be defined before or after an analysis has been run; however, it is safest to wait until after the analysis has been run. Typically do not define section cuts, and more importantly, the groups used in the section cut definition, until all manual meshing of the model (if any) has been completed (see Frame - Automatic Frame Mesh, Area - Automatic Area Mesh or Solid - Automatic Solid Mesh for more information about meshing). If the groups are defined before manual meshing, some of the point objects that should be in the group may not yet be created.
Define section cuts as follows:
Define the group that is used to specify the extent of the section cut as follows.
Select the objects that are to be part of the section cut.
Select the Assign menu > Assign to Group command to access the Assign/Define Group Names form.
Click the Add New Group button to access the Group Definition form.
Enter a name in the Group Name edit box. If it is not already checked, check the Section Cut Definition check box, and click the OK button.
Select the Add to Group option in the lower left-hand corner of the Assign/Define Group Names form and click the OK button.
Click the Define menu > Section Cuts command to access the Section Cuts form. Use the buttons on this form to add, modify, or delete section cuts.
Add Section Cut button. Click the Add Section Cut button to access the Section Cuts Data form, which has the following areas, options, and buttons:
Section Cut Name edit box. Use the default or type in a new name.
Coordinate System drop-down list. Choose the coordinate system in which the section cut will be defined.
Units drop-down list. Use the specified units or select new units from the drop-down list for the various values on the form.
Section Cut Defined By area. Choose an option for defining the section cut.
Group option. When this option is selected, section cut results are reported for all elements included in the Group specified using the Group drop-down list in the Section Cut Group area of the form.
Quadrilateral Cutting Planes option. When this option is selected, the Quadrilateral Cutting Planes spreadsheet area is added to the form, along with the Results Report Are on This Side of Elements area.
Quadrilateral Cutting Planes spreadsheet area. Use the cells of the spreadsheet to specify the coordinates for the four points that define the quadrilateral. Click the Check For Legal Quadrilateral button to verify that the points are valid. SAP2000 will display a message confirming or denying the validity of the coordinates.
Section cut results are reported for all elements that are fully cut by the quadrilateral and that have their associated objects included in the Group selected in the Group drop-down list in the Section Cut Group area of the form (see below).
Results Report Are on This Side of Elements area. Use the options in the area of the form to specify that the results are reported for the Positive 3 Axis Side of the Quadrilateral, or the Negative 3 Axis Side of the Quadrilateral. The 3 Axis is the Z axis.
Section Cut Group area. Select the name of the group that defines the section cut from the Group drop-down list.
Section Cut Result Type area. Choose the type of results to be reported, Analysis or Design. The options in the Section Cut Local Axes Orientation area at the bottom of the form vary depending on the type of results selected.
Section Cut Axes Orientation - Analysis. By default the positive local 1, 2 and 3 axes of the section cut correspond to the global X, Y and Z axis, respectively. Type in a value for rotation angles about the Z, Y’ and X” axes, in degrees (Y’ and X” are used as axes names instead of Y and X to emphasize that after an angle about Z has been specified, the local X and Y will change as a result).
Advanced Axes check box and Advanced button. Check this check box and click this button to access the Section Cut Advanced Axes form. Use the form to specify the axial reference vector and the local plane and its reference vectors for the specified section cut.
Section Cut Axes Orientation - Design. Choose to specify the orientation using the Wall, Spandrel, or Slab option.
Wall option. In this case, the Local 1 axis is parallel to the Global Z axis. The 2 and 3 axes lie in the global XY plane.
Spandrel or Slab option. In these cases, the Local 2 axis is parallel to the Global Z axis. The 1 and 3 axes lie in the global XY Plane.
Angle from Global X to Local 2 or Local 1 edit box. Use this edit box to specify the angle between the Global X and the Local 2 (Wall option) or Local 1 (Spandrel and Slab options) axis. A positive angle appears counterclockwise when viewed from above.
Results Reported Are on This Side of Elements area. Choose to report results on the Top or Bottom when the Wall option is selected, or the Right or Left side when the Spandrel or Slab option is selected.
Results Reported at this Location options. Define the location (point) about which section cut forces are summed. Choose from the following two options:
Note: A point object does not need to be defined at the point about which the section cut forces are being summed.
Default option. By default the section cut forces are reported at a location (point) that has coordinates equal to the average of the coordinates of all of the point objects included in the group that defines the section cut.
User-Defined option. Any arbitrary point can be specified about which section cut forces are to be summed by entering the global X, Y and Z coordinates of that point. Note it is not necessary that a point object be defined at the point about which the section cut forces are to be summed.
Modify/Show Section Cut button.
Highlight the name of the section cut to be modified in the Section Cuts area of the Section Cuts form.
Click the Modify/Show Section Cut button to access the Section Cuts Data form.
Use the drop-down lists and edit boxes on the Section Cuts Data form to modify the section cut as necessary. The various areas on the Section Cuts Data form are described under the "Add Section Cut Button" portion of this topic.
Delete Section Cut button.
Highlight the name of the section cut to be deleted in the Section Cuts area of the Section Cuts form.
Click the Delete Section Cut button to access the Section Cuts Data form.
After running an analysis, use the Display menu > Show Tables command to display the Choose Tables for Display form; click the Structure Output item and click the OK button to view the section cut forces.
Example: Use of this command is demonstrated in Problem N and Problem S.
See Also
Section Cut Output Conventions