The structural analysis software RFEM 6 is the basis of a modular software system. The main program RFEM 6 is used to define structures, materials, and loads of planar and spatial structural systems consisting of plates, walls, shells, and members. The program also allows you to create combined structures as well as to model solid and contact elements.
RSTAB 9 is a powerful analysis and design software for 3D beam, frame, or truss structure calculations, reflecting the current state of the art and helping structural engineers meet requirements in modern civil engineering.
Do you often spend too long calculating cross-sections? Dlubal Software and the RSECTION stand-alone program facilitate your work by determining section properties of various cross-sections and performing a subsequent stress analysis.
Do you always know where the wind is blowing from? From the direction of innovation, of course! With RWIND 3, you have a program at your side that uses a digital wind tunnel for the numerical simulation of wind flows. The program simulates these flows around any building geometry and determines the wind loads on the surfaces.
Are you looking for an overview of snow load zones, wind zones, and seismic zones? Then you are in the right place. Use the Geo-Zone Tool to determine quickly and efficiently snow loads, wind speeds, and seismic data according to ASCE 7‑16 and other international standards.
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The stability design checks according to EN 1999‑1‑1, 6.3, are not included in RSECTION 1.
According to EN 1999‑1‑1, 5.2.2 (5) a), the stability analysis may be performed as a cross-section design, provided that a spatial calculation according to the second-order analysis is performed while applying global and local imperfections. In order to model the lateral-torsional buckling, it is necessary to determine the internal forces according to the geometrically nonlinear torsional buckling analysis with regard to warping torsion. It is only necessary to perform the section design, as all stability effects are covered by the calculation.
In RSECTION 1, you can calculate the stresses due to the axial force, biaxial bending moments and shear forces, primary and secondary torsional moment, as well as warping bimoment for any cross-section shape. This way, you can use the design method described in EN 1999‑1‑1, 5.2.2 (5) a) in RSECTION 1.
Using the Effective Sections (Extension for RSECTION 1) add-on, you can also perform a classification and calculate the effective cross-section according to EN 1999‑1‑1.
In the RSECTION program, you can analyze general steel or aluminum cross-sections and determine the effective section properties. For this, you need the Effective Sections program extension of RSECTION. If you have licensed this add-on, you can activate the Effective Section option for the calculation in the Base Data of the cross-section.
Then, define the standard according to which the calculation should be performed. Currently, the following options are available:
The effective section properties depend on the internal forces of the cross-section. Therefore, create a load case and define one or more internal force constellations.
After the calculation, the effective section properties are displayed in the table. In the graphic, you can check the stresses on the effective section.
Once you have saved the cross-section, you can import it into RFEM or RSTAB to use it for further analyses.
The webinar Determination of Section Properties and Stress Analysis in RSECTION shows the modeling and calculation of a cold-formed section. You can find further information there.
Both RFEM and RSTAB provide solution: There are numerous European and international standards as well as add-ons available for both programs that can facilitate your daily design work of aluminum and lighweight structures.
Main Programs RFEM and RSTAB
The main programs RFEM and RSTAB are used to define the model with its properties and actions. In addition to spatial beam structures, such as scaffolding or frame structures, you can also model membrane structures with RFEM. Thus, RFEM is the more versatile variant—especially if you work in other areas, such as solid construction.
Available Standards
Add-ons for Aluminum and Lightweight Structure
Design add-ons supplement the functionality of the main programs. Use the Aluminum Design add-on to perform the ultimate and serviceability limit state design, as well as the stability analysis according to the standards listed above. The Torsional Warping (7 DOF) add-on allows you to also perform lateral-torsional buckling analysis with up to seven degrees of freedom.
The design checks can be carried out for a large number of standardized and parameterized cross-sections. Lightweight structures often includes special cross-sections, such as extruded sections. You can define it with the program RSECTION and use it for the design in RFEM or RSTAB.
In the case of membrane and cable structures, the Form-Finding add-on facilitates your task to determine the shape of member and surface models subjected to axial forces.
In case of any questions about the Dlubal solution for aluminum and lightweight structures, our sales team will be happy to assist you.
Channels, hats, angles, and Z sections from AISI D100-17 standard can be designed according to AISI S100 in the Steel Design Add-on.
Additionally, all rectangular and round HSS AISC shapes can also be designed per AISI S100. This option is set under the Strength Configuration for Steel Design.
A custom section can be created using one of the “Thin-Walled” sections available in the library. For other sections that do not meet any of the 14 available cold-formed shapes, the sections can be created and imported from the stand-alone program RSECTION.
Parametric (custom) sections with the manufacturing type “Cold formed” can be designed according to AISI S100 or CSA S136.
The safety factor Ω and resistance factor Φ used in Chapters E through H are only appropriate for sections that comply with the limitations in Table B4.1‑1. For all other sections that exceed any of the limits, higher safety factors Ω or lower resistance factors Φ are applied according to section A1.2(C). In RFEM, this limitation is checked by default. The user has the option to deactivate this check in the "Strength Configuration".
Shapes that can be checked in RFEM include C, Z, L, I (double back-to-back C), hat, rectangular, and round HSS. In the example shown in Image 02, the 8ZS2.75 x 105 section meets the applicability limits.
For general/complex sections, such as the sigma section used in Example III‑14 of AISI D100‑17 (shown in Image 03), the more conservative factors are automatically applied. As a result, Φc = 0.80 is used in the RFEM design checks. However, the manual calculation shows that the sigma section actually meets the applicability limits and Φc = 0.85 can be used instead.