Steel Frame Structure with Tension Members
Model to Download
For the stability design of members and sets of members with a uniform cross-section, you can use the equivalent member method according to EN 1993-1-1, 6.3.1 to 6.3.3. However, as soon as a tapered cross-section is available, this method can no longer be used or only to a limited extent. This model was used to show how RF-/STEEL EC3 recognizes such cases automatically and switches to the General Method.
Model Used in
The following article describes the design of a single‑span beam subjected to bending and compression, which is performed according to EN 1993‑1‑1 in the RF‑/STEEL EC3 add‑on module. Since the beam is modeled with a tapered cross‑section, thus not a uniform structural component, the design must be performed either according to the General Method in compliance with Ch. 6.3.4 of EN 1993‑1‑1, or according to the second‑order analysis. Both options will be explained and compared, and for the calculation according to the second‑order analysis, an additional design format using the Partial Internal Forces Method (PIFM) is available. Therefore, the design is divided into three steps:
- Design according to Ch. 6.3.4 of EN 1993‑1‑1 (General Method)
- Design according to the second‑order analysis, elastic (warping torsion analysis)
- Design according to the second‑order analysis, plastic (warping torsion analysis and Partial Internal Forces Method)
SHAPE-THIN determines the effective cross-sections according to EN 1993-1-3 and EN 1993-1-5 for cold-formed sections. You can optionally check the geometric conditions for the applicability of the standard specified in EN 1993‑1‑3, Section 5.2.
The effects of local plate buckling are considered according to the method of reduced widths and the possible buckling of stiffeners (instability) is considered for stiffened sections according to EN 1993-1-3, Section 5.5.
As an option, you can perform an iterative calculation to optimize the effective cross-section.
You can display the effective cross-sections graphically.
Read more about designing cold-formed sections with SHAPE-THIN and RF-/STEEL Cold-Formed Sections in this technical article: Design of a Thin-Walled, Cold-Formed C-Section According to EN 1993-1-3.
- For the design of a set of members in STEEL EC3, I cannot define effective lengths. Am I doing something wrong?
- How can I display membrane stresses in the results of RF‑STEEL Surfaces?
- What is the meaning of the superposition according to the CQC rule in a dynamic analysis??
- How is the automatic creation of c/t-parts carried out?
- I design a set of members by using the equivalent member method in RF‑/STEEL EC3, but the calculation fails. The system is unstable, delivering the message "Non-designable - ER055) Zero value of the critical moment on the segment."What could be the reason?
- My aim is to mesh a circular hole plate in a mapped way. Is such a meshing possible in RFEM?
- The design ratio of the cross-section check is different for the RF‑/STEEL and RF‑/STEEL EC3 add-on module. What is the reason?
- What is the meaning of the warning message ER061) Minimum amplifier of design loads <1?
- How can I optimize the calculation time in CRANEWAY?
- I would like to define lateral supports along the axis of a structural component that sometimes act on the upper flange, sometimes on the lower flange. However, it is only possible to select one item for each member. How can I create the entry?