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Sections

The Cross -Sections table as well as the navigator category 'Stress-Strain Analysis' lists all cross-sections available in the model with the corresponding materials. The specifications of the cross-section types are only informative.

Remove cross-sections from analysis

For all valid cross-sections, you can exclude all members from the stress-strain analysis by clearing the 'To Analyze' check box to which this material is assigned. Thus, the members are sorted in the tables Objects to be Analyzed - Stresses and Objects to be Analyzed - Stress Ranges in the column 'Not Valid/Deactivated' and removed from the analysis.

Use other section for analysis

If you want to use a different cross-section for the stress analysis than for the RFEM calculation, you can specify an alternative in the 'Use Other Cross-Section for Analysis' column. To do this, use the button Edit Object , to select a different cross-section in the library.

Info

This action has no influence on the internal forces: They are also used for the modified cross-section in the stress analysis.

To change the cross-section generally - thus also for the model - double-click the table row or click the button Open Editing Dialog Box dialog box for editing the cross-section in the table toolbar. There, you can assign a different cross-section from the library.

Tip

The RSECTION program allows you to define any cross-sections and use them for a stress-strain analysis.

Optimizing Cross-Section

All standardized and parametrized cross-sections can be optimized within the current series. You can access the optimization via the list in the 'Use Other Section for Analysis' column.

During the optimization, RFEM determines the smallest possible cross-section in the series, whose utilization is lower than in the Global Settings dialog box. For this "simplified cross-section optimization", the same conditions apply as for the use of an alternative cross-section described above: During optimization, the design checks are carried out with the internal forces of the model. The optimal variant is then entered into the table.

Important

The cross-section optimization in the add-on does not take into account how the modified cross-sections affect the stiffnesses and internal forces of the model. Therefore, you should transfer the optimized cross-sections to the model and perform a recalculation for the final analysis. Use the cell shortcut menu.

As soon as another cross-section is backgrounded, further options are available in the cell shortcut menu (opens by right-clicking it):

  • Use Optimized Section in Model
  • Use all optimized cross-sections in the model
  • Use Section from Model in Addon
  • Use All Sections from Model in Addon

For a comprehensive model optimization, we recommend the https://www.dlubal.com/en-US/products/add-ons-for-rfem-6-and-rstab-9/special-solutions/optimization-costs-co2-software add-on Emissions Estimation Optimization Costs/CO2 Emission Estimation].

Tip

After the calculation, the 'Max. Design ratio' added (see Image Import other cross-section from library). It is intended to be a decision support
Optimization, since you can quickly recognize over- or undersized cross-sections.

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