New Section

After clicking on the Section dialog, a new dialog is displayed with the following tabs:

• Standard
• Parametric
• Tapered
• Compound
• Special
• Ax, Iy, Iz.

Note: All the following descriptions and the description of all tabs are for steel sections (the tabs for timber and aluminum sections look similar). If a concrete section type (such as, RC column or RC beam) is selected in the Sections dialog, the New Section dialog looks different.

Available cross section types include:

• RC columns (section type - RC column): rectangular, T-shaped, L-shaped, Z-shaped, regular-polygon-shaped, circular, circle half, and circle quarter
• RC beams/ continuous footings (section type - RC beam):rectangular, T-shaped, I-shaped.

For example, the New Section dialog for an RC beam displays as shown in the following image:

The Section dialog lets you:

1. Select the beam section type (rectangular, T-shaped, I-shaped, T-shaped with flanges positioned lower) and specify its dimensions.
2. Specify section name. By default, Robot enters a section name composed of a few letters denoting the section type and the dimensions of the cross-section.
3. Select the color of the section.

You can select 1 of 4 types of beam/continuous footing sections: rectangular, T-shaped, I-shaped, and T-shaped with lower-positioned flanges. The dialog displays the parameters for the type of section selected. The previous dialog shows the parameters for a rectangular section. Similar options are displayed in the dialog when a T-shaped section is selected. After a T-shaped section with lower-positioned flanges is selected, 2 additional tabs display in the dialog: Slabs and Cuts.

Selecting the Use tapered section option, assigns linearly-varying cross-sections to a beam by specifying in the h2 field, a value of the height at the right end of the selected segment.

The Reduction of mom. of inertia option lets you specify coefficients reducing the section's moments of inertia (Ix, Iy, or Iz) in a section definition (RC beam or RC column). The reduction is associated with properties of a given section and it is not a global anlaysis parameter. Reduced moments of inertia are displayed (in tables or in dialogs) as current section properties. Reduced properties are considered in static calculations and are transferred to the design modules.

Reduction of the moments of inertia for RC sections are applied to static calculations to account for section cracking. This method is allowed by USA codes (UBC 1997 point 1910.11.1 or ACI 318 p.10.11.1) as well as other codes.

Tabs display the recent parameters settings. When they are opened for the first time, they have the following default settings:

• Standard sections from the database: I-sections, first configuration database, family 'all', steel member type, GAMMA angle=0
• User sections: rectangle, all fields are empty except for: section type: steel, GAMMA angle = 0
• Tapered sections: rectangle, all fields are empty, except for: section type: steel, GAMMA angle = 0
• Sections defined by the geometric parameters values: all fields are empty, section type: steel, GAMMA angle = 0

You can transfer data only between the Parametric and the Tapered tabs. If a section type and its parameters are defined in the parametric section, after changing to the Tapered tab the section type goes with the member type, the GAMMA angle, and the parameter values which are entered as the section dimensions at the member's beginning node.

At the bottom of the dialog, a field displays the name of the material assigned to the section.

See also:

Some section symbols

Section Database