The three types of moment frames (Ordinary, Intermediate, Special) are available in the Steel Design add-on of RFEM 6. The seismic design result according to AISC 341-22 is categorized into two sections: member requirements and connection requirements.
Compliance with building codes, such as Eurocode, is essential to ensure the safety, structural integrity, and sustainability of buildings and structures. Computational Fluid Dynamics (CFD) plays a vital role in this process by simulating fluid behavior, optimizing designs, and helping architects and engineers meet Eurocode requirements related to wind load analysis, natural ventilation, fire safety, and energy efficiency. By integrating CFD into the design process, professionals can create safer, more efficient, and compliant buildings that meet the highest standards of construction and design in Europe.
Both the determination of natural vibrations and the response spectrum analysis are always performed on a linear system. If nonlinearities exist in the system, they are linearized and thus not taken into account. They are caused by, for example, tension members, nonlinear supports, or nonlinear hinges. This article shows how you can handle them in a dynamic analysis.
The CSA S16:19 Stability Effects in Elastic Analysis method in Annex O.2 is an alternative option to the Simplified Stability Analysis Method in Clause 8.4.3. This article will describe the requirements of Annex O.2 and application in RFEM 6.
To be able to evaluate the influence of local stability phenomena of slender structural components, RFEM 6 and RSTAB 9 provide you with the option of performing a linear critical load analysis on the cross-section level. The following article explains the basics of the calculation and the result interpretation.
Windbreak structures are special types of fabric structures which protect the environment from harmful chemical particles, abate wind erosion, and help to maintain valuable sources. RFEM and RWIND are used for wind-structure analysis as one-way fluid-structure interaction (FSI).
This article demonstrates how to structural design windbreak structures using RFEM and RWIND.
The design of an Ordinary Concentrically Braced Frame (OCBF) and a Special Concentrically Braced Frame (SCBF) can be carried out in the Steel Design add-on of RFEM 6. The seismic design result according to AISC 341-16 and 341-22 is categorized into two sections: Member Requirements and Connection Requirements.
Moment frame design according to AISC 341-16 is now possible in the Steel Design add-on of RFEM 6. The seismic design result is categorized into two sections: member requirements and connection requirements. This article covers the required strength of the connection. An example comparison of the results between RFEM and the AISC Seismic Design Manual [2] is presented.
The three types of moment frames (Ordinary, Intermediate, Special) are available in the Steel Design add-on of RFEM 6. The seismic design result according to AISC 341-16 is categorized into two sections: member requirements and connection requirements.
The Steel Design add-on in RFEM 6 now offers the ability to perform seismic design according to AISC 341-16 and AISC 341-22. Five types of seismic force-resisting systems (SFRS) are currently available.
This example is described in technical literature [1] as Example 9.5 and in [2] as Example 8.5. A lateral-torsional buckling analysis must be performed for a principal beam. This beam is a uniform structural member. Therefore, the stability analysis can be carried out according to Clause 6.3.3 of DIN EN 1993‑1‑1. Due to the uniaxial bending, it would also be possible to perform the design using the General Method according to Clause 6.3.4. Additionally, the determination of the critical load factor is validated with an idealized member model in line with the method mentioned above, using an FEM model.
The stability checks for the equivalent member design according to EN 1993-1-1, AISC 360, CSA S16, and other international standards require consideration of the design length (that is, the effective length of the members). In RFEM 6, it is possible to determine the effective length manually by assigning nodal supports and effective length factors or, on the other hand, by importing it from the stability analysis. Both options will be demonstrated in this article by determining the effective length of the framed column in Image 1.
This technical article presents some basics for using the Torsional Warping add-on (7 DOF). It is fully integrated into the main program and allows you to consider the cross-section warping when calculating member elements. In combination with the Stability Analysis and Steel Design add-ons, it is possible to perform the lateral-torsional buckling design with internal forces according to the second-order analysis, taking imperfections into account.
Structure stability is not a new phenomenon when referring to steel design. The Canadian steel design standard CSA S16 and the most recent 2019 release are no exception. Detailed stability requirements can be addressed with either the Simplified Stability Analysis Method in Clause 8.4.3 or, new to the 2019 standard, the Stability Effects in Elastic Analysis method provided in Annex O.
The advantage of the RFEM 6 Steel Joints add-on is that you can analyze steel connections using an FE model for which the modeling runs fully automatically in the background. The input of the steel joint components that control the modeling can be done by defining the components manually, or by using the available templates in the library. The latter method is included in a previous Knowledge Base article titled “Defining Steel Joint Components Using the Library". The definition of parameters for the design of steel joints is the topic of the Knowledge Base article “Designing Steel Joints in RFEM 6".
Steel connections in RFEM 6 are defined as an assembly of components. In the new Steel Joints add-on, universally applicable basic components (plates, welds, auxiliary planes) are available for entering complex connection situations. The methods with which connections can be defined are considered in two previous Knowledge Base articles: “A Novel Approach to Designing Steel Joints in RFEM 6" and “Defining Steel Joint Components Using the Library".
Designing rigid end plate connections is difficult for four-row connection geometries and multi-axis bending stresses, because there are no official design methods.
This technical article deals with the design of structural components and cross-sections of a welded truss girder in the ultimate limit state. Furthermore, the deformation analysis in the serviceability limit state is described.
Closed circular cross-sections are ideal for welded truss structures. The architecture of such constructions is popular when designing transparent roofs. This article shows the special features of the connection design using hollow sections.
The European standard EN 1993-1-8, Section 4.5.3.3. provides the user with a simplified method for the ultimate limit state design of fillet welds. According to the standard, the design is fulfilled if the design value of the resultant acting on the fillet weld area is smaller than the design value of the weld's load-bearing capacity. Thus, if you want to dimension the weld for a surface model, you will be faced with a variety of results due to the nature of FEM calculations. Therefore, we show in the following text how to determine the force components from the model.
This technical article deals with the stability analysis of a roof purlin, which is connected without stiffeners by means of a bolt connection on the lower flange to have a minimum manufacturing effort.
Both the determination of natural vibrations and the response spectrum analysis are always performed on a linear system. If nonlinearities exist in the system, they are linearized and thus not taken into account. Straight tension members are very often used in practice. This article will show how you can display them approximately correctly in a dynamic analysis.
Utilize the RF-/STEEL Cold-Formed Sections module extension to perform ultimate limit state designs of cold-formed sections according to EN 1993-1-3 and EN 1993-1-5. In addition to the cold-formed cross-sections from the cross-section database, you can design general cross-sections from SHAPE-THIN.
The design of cold-rolled steel products is defined in EN 1993-1-3. Typical cross-section shapes are channel, C, Z, top hat, and sigma sections. These are cold-rolled steel products made of thin-walled sheet metal that has been cold-formed by roll-forming or bending methods. When designing the ultimate limit states, it is also necessary to ensure that local transverse forces do not lead to compression, crippling of the web, or local buckling in the web of the sections. These effects can be caused by local transverse forces by the flange into the web, as well as by support forces at the supported points. Section 6.1.7 of EN 1993-1-3 specifies in detail how to determine the resistance of the web Rw,Rd under local transverse forces.
This technical article analyzes the effects of the connection stiffness on the determination of internal forces, as well as the design of connections using the example of a two-story, double-spanned steel frame.
In this technical article, a hinged column with a centrally acting axial force and a line load acting on the strong axis will be designed by means of the RF-/STEEL EC3 add-on module according to EN 1993-1-1.
A welded connection of an HEA cross-section under biaxial bending with axial force will be designed. The design of welds for the given internal forces according to the simplified method (DIN EN 1993-1-8, Clause 4.5.3.3) by means of SHAPE-THIN will be performed.
This example will show what you should consider when you perform column design for bending and compression with regard to the internal forces from load combinations and result combinations.
The fire resistance design can be performed according to EN 1993-1-2 in RF-/STEEL EC3. The design is carried out according to the simplified calculation method for the ultimate limit state. Claddings with different physical properties can be selected as fire protection measures. You can select the standard temperature-time curve, the external fire curve, and the hydrocarbon curve to determine the gas temperature.