All cross-sections available in the model are listed again in the Input Data of the design add-on.
Allowable Cross-Sections
The font color of the cross-section gives you the information about the utilization and validity of a cross-section in the selected design add-on:
- Blue = a cross-section not used in the entire model
- Red = a cross-section not suitable for the design in the active add-on
- Gray = Members / member set with this cross-section are not selected for design in the active add-on.
- Black = Members / member sets with this cross-section are selected for design in the active add-on.
In the aluminum design, only cross-sections with materials of the Aluminum type are allowed (see also Chapter Materials). Regardless of the selection in the "To Design" check box, objects with invalid materials are not considered in the design (an automatic classification in "Not Valid / Deactivated"). Furthermore, there are restrictions regarding the cross-section type.
Removing Cross-Sections from Design
For all valid cross-sections, you can deactivate all objects with this cross-section by clearing the "To Design" check box. Thus, these objects are assigned to the "Not Valid / Deactivated" column and removed from the design (see Objects to Design).
Section Type
The section type of a cross-section provides the information about the possible design. Some cross-section types are not allowed for the design in the add-on or can only be used with restrictions. The following cross-section types are allowed in the Aluminum Design:
- Standardized - Steel
- Parametric - Thin-Walled
- Parametric - Bars
- Built-up - Steel
- General by RSECTION
Using Different Cross-Section for Design
If you want to use a different cross-section for the design than for the RFEM calculations, you can select the cross-section to be used for each cross-section. This does not affect the internal forces, which are also used for the design of the other cross-section.
If a different cross-section is entered in this column, further options are available in the shortcut menu (Export Section to RFEM, Export All Sections to RFEM, Import Section from RFEM, Import All Sections from RFEM).
Simplified Cross-Section Optimization
For standardized cross-sections, it is possible to optimize the cross-sections from their respective series of the cross-section library. In this case, the program searches for the smallest possible cross-section from the corresponding row, for which all design checks provide a smaller design criterion than the limit value defined in the Global Settings.
For this simplified cross-section optimization of the standardized cross-sections, the same boundary conditions apply as for using another cross-section for the design. With the given internal forces, the design checks are carried out for all cross-section variants to be optimized and then the optimal variant is displayed.
Therefore, the final design requires transferring the optimized cross-sections to RFEM and performing the calculation again. Comprehensive structural optimization is only possible with the Optimization & Costs / CO2 Emission Estimation add-on.
Adjusting Cross-Sections
Section properties can be adjusted in the editing dialog box of the cross-section. Double-click a row or click the
button to go directly to the editing dialog box of the cross-section.
The "Options" column includes the icons for various existing settings or modified values, so you can quickly get an overview and, for example, identify the cross-sections calculated according to the thin-walled theory.
To create and design any cross-section, you can use the RSECTION program.
Special Features of RSECTION Cross-Section Design
If there are no elements defined in an RSECTION cross-section, the thickness of the individual cross-section parts cannot be determined. The design is then carried out using the material properties of the first thickness range.
For the RSECTION cross-sections without elements and thus without the subpanels for local buckling, the elastic design of the cross-section is carried out. A check of the c/t ratios and design checks for local buckling are then not possible.