Formula 3
Do you have any questions?
![Basic Types of Cross-Section Parts](/en/webimage/014717/2944998/01-en.png?mw=512&hash=65e98cfe859ce35a3e3e9da47a0ef9335401520e)
The classification of cross-sections is intended to determine the limits of resistance and rotational capacity due to local buckling of cross-section parts. In EN 1999‑1‑1, 6.1.4.2 (1), four classes are defined.
![Cross-Section Classes](/en/webimage/009823/2420607/01-en-png-png.png?mw=512&hash=6ca63b32e8ca5da057de21c4f204d41103e6fe20)
The RF-/STEEL EC3 add‑on module performs a detailed cross‑section classification on each design before the design is carried out. Thus, the susceptibility to local buckling of all cross-section parts is evaluated. The defined cross-section class has an effect on the resistance and rotational capacity determination.
![Setting Section from Library](/en/webimage/009751/2420187/01-en-png-png.png?mw=512&hash=6ca63b32e8ca5da057de21c4f204d41103e6fe20)
SHAPE‑THIN cross‑section properties software determines the effective section properties of thin‑walled cross‑sections according to Eurocode 3 and Eurocode 9. Alternatively, the program allows plastic design of general cross‑sections according to the Simplex Method. In this process, plastic cross-section reserves are iteratively calculated for elastically determined internal forces. The following example describes the effective cross-section properties in the notching area of a rolled I-section. Afterwards, the results are compared with the plastic analysis.
![Manual Selection of Cross-Section Class](/en/webimage/010346/3014464/1_Manual_Definition_of_Cross-Section_Class.png?mw=512&hash=04f5243151ba895864e6d51f4e60d40867eaad56)
In the default setting, the cross-section class for each member and load case is determined automatically in the design modules. In the input window of the cross sections, however, the user can also specify the cross-section class manually; for example, if local buckling is excluded by the design.
![Feature 002820 | Limit Plastic Strain for Welds](/en/webimage/050344/3881226/1.png?mw=512&hash=9d7f6c198b6d4ae6ee8f2fa8bca75f85579e14c9)
In the ultimate configuration of the steel joint design, you have the option to modify the limit plastic strain for welds.
![Component "Base Plate"](/en/webimage/050345/3936120/50345.png?mw=512&hash=3bd641cb1a2445804b338855e4debfc40c6563e9)
The "Base Plate" component allows you to design base plate connections with cast-in anchors. In this case, plates, welds, anchorages, and steel-concrete interaction are analyzed.
![Feature 002807 | 3D Display of FSM Results](/en/webimage/049281/3861162/2024-05-01_10-32-55.png?mw=512&hash=2377d291bc20ac3d78d617b50c131614e99ac6f7)
In the "Edit Section" dialog box, you can display the buckling shapes of the Finite Strip Method (FSM) as a 3D graphic.
![Steel Design | Seismic Force-Resisting System Design Overview](/en/webimage/048507/3803346/seismic_steel.png?mw=512&hash=1c18a83f050e74601a7300444a0d77a0246a0e02)
- Design of five types of seismic force-resisting systems (SFRS) includes Special Moment Frame (SMF), Intermediate Moment Frame (IMF), Ordinary Moment Frame (OMF), Ordinary Concentrically Braced Frame (OCBF), and Special Concentrically Braced Frame (SCBF)
- Ductility check of the width-to thickness ratios for webs and flanges
- Calculation of the required strength and stiffness for stability bracing of beams
- Calculation of the maximum spacing for stability bracing of beams
- Calculation of the required strength at hinge locations for stability bracing of beams
- Calculation of the column required strength with the option to neglect all bending moments, shear, and torsion for overstrength limit state
- Design check of column and brace slenderness ratios