The Criteria > Reduced Beam Section command provides a means of specifying the flange cut dimensions to be used for beams assigned to use the Reduced Beam Section connection type. For convenience the list automatically contains all of the sizes assigned to the Frame beams that have been assigned the Reduced Beam Section Connection type. If new sizes are subsequently assigned to the frames, those sizes will automatically be added to the list. The cut dimensions a, b, and c are also listed, and can be edited.

Section 5.8 of AISC 358-16 specifies the range of acceptable values of a, b, and c, based on multipliers time the beam width or depth. From that range, the desired multipliers should be specified in the Default Dimensions section. This is important because the program will use these defaults as necessary to calculate a, b, and c even if this criteria command is not invoked prior to analysis.

When calculating flange cut values, the values will be rounded to the nearest multiple of the specified increment, except rounded as necessary not to be less than the minimum value nor greater than the maximum value specified by AISC 358.

Modifying flange cut properties a, b, and c:

• Individual values can be modified by directly editing them in the table.
• Values for a Size can be modified by modifying the Default Dimensions, selecting the size from the table, and then selecting the Reset button.
• Values for all Sizes can be modified by modifying the Default Dimensions and then selecting the Reset All button.

Sizes can be deleted from the list by selecting the size in the table and then selecting the Delete button. It is not necessary to delete unused sizes. If a size is deleted from the table but is assigned to a Frame beam, it will subsequently be re-added to the list, with flange cut dimensions based on the Default Dimensions.

Flange cut properties will only be applied to beams that have been assigned to have the Reduced Beam Section connection type using the Assign > Beams > Frame Beam Connection Types command; for all other beams these flange cut dimensions will be ignored.

See Assign Frame Beam Connection Types for information on assigning beams to use the Reduced Beam Section connection.