Beam in Flexure According to ADM 2020

In the case of open cross-sections, the torsional load is removed mainly via secondary torsion, since the St. Venant torsional stiffness is low compared to the warping stiffness. Therefore, warping stiffeners in the cross-section are particularly interesting for the lateral-torsional buckling analysis, as they can significantly reduce the rotation. For this, end plates or welded stiffeners and sections are suitable.

The support conditions of a beam subjected to bending are essential for its resistance to lateral-torsional buckling. If, for example, a single-span beam is held laterally in the middle of the span, the deflection of the compressed flange can be prevented, and a two-wave eigenmode can be enforced. The critical lateral-torsional buckling moment is increased significantly by this additional measure. In the add-on modules for member design, different types of lateral supports on a member can be defined using the "Intermediate supports" input window.

If an aluminum member section is comprised of slender elements, failure can occur due to the local buckling of the flanges or webs before the member can reach full strength. In the add-on module RF-/ALUMINUM ADM, there are now three options for determining the nominal flexural strength for the limit state of local buckling, M_nlb, from Section F.3 in the 2015 Aluminum Design Manual. The three options include sections F.3.1 Weighted Average Method, F.3.2 Direct Strength Method, and F.3.3 Limiting Element Method.

You know for sure that when connecting tension-loaded components with bolted connections, you need to consider the cross-section reduction due to the bolt holes in the ultimate limit state design. The structural analysis programs also have a solution for this. In the Aluminum Design add-on, you can enter a member local section reduction for this. Enter the reduction of the cross-section as an absolute value or as a percentage of the total area at all relevant locations.

Did you use the eigenvalue solver of the add-on to determine the critical load factor within the stability analysis? In this case, you can then display the governing mode shape of the object to be designed as a result.

• Calculation of deflections and comparison with the normative or manually adjusted limit values
• Consideration of a precamber for the deflection analysis
• Different limit values are possible, depending on the design situation type
• Manual Adjustment of Reference Lengths and Segmentation by Direction
• Calculation of deflections related to the initial structure or to the deformed structure
• Further detailed design checks depending on the selected design standard (for example, vibration design according to EN 1999‑1‑1, 7.2.3)
• Graphical result display integrated in RFEM/RSTAB; for example, the design ratio of a limit value, or the deformation or the sag
• Complete integration of the results into the RFEM/RSTAB printout report