Sometimes a structure needs reinforcement in cases where a new floor is being added, or when an existing member is found to be under design due to a hard-to-predict loading assumption. In many cases, the structural member may not be easily replaced, and reinforcement is implemented to meet the new loading requirement.
Utilizing the RF-STEEL AISC add-on module, steel member design is possible according to the AISC 360-16 standard. The following article will compare the results between calculating lateral torsional buckling according to Chapter F and Eigenvalue Analysis.
The design of a torsional loaded beam according to AISC Design Guide 9 will be shown, based on a verification example. The design will be performed with the RF‑STEEL AISC add-on module and the RF‑STEEL Warping Torsion module extension with 7 degrees of freedom.
Part 4.1 of this article series describes the connection of the RF‑/STEEL EC3 add‑on module; the members and load combinations to be designed were already defined. This section will focus on the optimization of cross‑sections in the module and the transfer to RFEM. The elements already explained in the previous parts are not described again.
The boundary conditions of a plate support can be entered quickly as singular and line supports in the FEA software. However, if the flexibility of the supports is not considered when modeling the structure, it is often necessary to take a closer look at the support definitions during the design using stresses or the determination of the required reinforcement, at the latest.
With RFEM 5.06 and RSTAB 8.06, the examples and help files for programming the COM interface are not only available on the Internet, they are also included in the installation. To find them, look for the "SDK" folder in the project directory (usually C:\Users\Public\Documents\Dlubal).
The "Result Beam" member type has been available since the release of RFEM 5. The result beam is a virtual member that does not have any stiffness nor require any support. It can be used in various situations in order to integrate the results from members, surfaces, and solids, and to display them as member internal forces.
In RF-STEEL Surfaces, it is possible to display the stresses relevant for the design of welds, for example, according to EN 1993‑1‑8, Figure 4.5. When evaluating the stress components, the local xyz-axis system of the surfaces must be considered.