To evaluate whether it is also necessary to consider the second-order analysis in a dynamic calculation, the sensitivity coefficient of interstory drift θ is provided in EN 1998‑1, Sections 2.2.2 and 4.4.2.2. It can be calculated and analyzed using RFEM 6 and RSTAB 9. The coefficient θ is calculated as follows:$$\mathrm\theta\;=\;\frac{\displaystyle{\mathrm P}_\mathrm{tot}\;\cdot\;{\mathrm d}_\mathrm r}{{\mathrm V}_\mathrm{tot}\;\cdot\;\mathrm h}\;$$
For the ultimate limit state design, EN 1998‑1, Sections 2.2.2 and 4.4.2.2 require a calculation considering the second‑order theory (P‑Δ effect). This effect may be neglected only if the interstory drift sensitivity coefficient θ is less than 0.1.
Everything is online. The same is true for the Dlubal licenses for RFEM 6, RSTAB 9, and RSECTION. This article contains information about using and managing online licenses, reserving licenses, checking the license validity, and moving authorizations between the licenses.
The response spectrum analysis is one of the most frequently used design methods in the case of earthquakes. This method has many advantages. The most important is the simplification: It simplifies the complexity of earthquakes so far that the design can be performed with reasonable effort. The disadvantage of this method is that a lot of information is lost due to this simplification. One way to moderate this disadvantage is to use the equivalent linear combination when combining the modal responses. This article explains this option by describing an example.
Our webservice offers users the opportunity to communicate with RFEM 6 and RSTAB 9 using various programming languages. Dlubal's high-level functions (HLFs) allow you to expand and simplify the WebService's functionality. In line with RFEM 6 and RSTAB 9, using our WebService makes the engineer's work easier and faster. Check it out now! This tutorial shows you how to use the C# library by means of a simple example.
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.
With the Steel Design add-on, you can design structural steel components in the event of fire using the simple design methods according to Eurocode 3. The component temperature at the time of the design check can be determined automatically according to the temperature-time curves specified in the standard. In addition to considering a cladding for fire protection, it is also possible for you to take account of the beneficial properties of hot-dip galvanization.
This article shows how the “Time-Dependent Analysis” add-on is integrated in RFEM 6 and RSTAB 9. It describes how to define input data such as the time-dependent characteristics of the material, how to determine the type of analysis and how to specify loading times.
As for the previous generations of Dlubal programs, an integrated interface with Autodesk Revit is now also available for RFEM 6 and RSTAB 9. This article will provide some general information about the interface as well as the Dlubal-relevant structural objects and parameters in Revit.
The Steel Joist Institute (SJI) previously developed Virtual Joist tables to estimate the section properties for Open Web Steel Joists. These Virtual Joist sections are characterized as equivalent wide-flange beams which closely approximate the joist chord area, effective moment of inertia, and weight. Virtual Joists are also available in the RFEM and RSTAB cross-section database.
In the RFEM 6 and RSTAB 9 programs, it is possible to group objects based on different criteria. Hence, objects that meet the defined criteria can be selected and edited at the same time. This is possible with the “Object Selection” tool, which is comparable to “Special Selection” in RFEM 5. This article will show you how to group objects with “Object Selection" as a new guide object of RFEM 6 or RSTAB 9.
RWIND 2 is a program for generating wind loads based on CFD (Computational Fluid Dynamics). The wind flow numerical simulation is generated around any building, including irregular or unique geometry types, to determine the wind loads on surfaces and members. RWIND 2 can be integrated with RFEM/RSTAB for the structural analysis and design or as a stand-alone application.
The API for RFEM 6, RSTAB 9, and RSECTION is based on the WebService concept. To get a good introduction to the subject, the following article will explain a further example in C#.
This article shows you how to define different types of member transverse stiffeners in RFEM 6 and RSTAB 9. It also shows you how to consider them in the design as well as the calculation of members with 7 degrees of freedom.
RFEM and RSTAB programs provide parameterized input as an advantageous product feature to create or adjust models by means of variables. This article will show you how to define global parameters and use them in formulas to determine numerical values.
The stand-alone program RSECTION is at your disposal for determining section properties and performing stress analysis for thin-walled and massive cross-sections. The program can be connected to both RFEM and RSTAB so that sections from RSECTION are also available in the RFEM and RSTAB library. Likewise, internal forces from RFEM and RSTAB can be imported into RSECTION.
The dynamic analysis in RFEM 6 and RSTAB 9 is divided into several add-ons. The Modal Analysis add-on is a prerequisite for all other dynamic add-ons, since it performs the natural vibration analysis for member, surface, and solid models.
Webservice is a communication between machines and programs. This communication is provided via the network and can, therefore, be used by any program that can send and receive strings via the HTTP protocol. RFEM 6 and RSTAB 9 provide an interface based on these cross-platform webservices. This tutorial shows the basics using the VBA programming language.
With the release of the structural analysis programs RFEM 6, RSTAB 9, RSECTION 1, and RWIND 2, Dlubal Software introduces a new generation of structural analysis programs. True to the motto "Structural analysis that is fun ...", the program provides users with universal tools with which they can meet all the requirements in structural engineering. Find out more about the latest developments at Dlubal Software in this article.
RSECTION 1 is a stand-alone program for determining section properties for both thin-walled and massive cross-sections, as well as for performing a stress analysis. In addition, the program can be connected to both RFEM and RSTAB: sections from RSECTION are available in the RFEM/RSTAB libraries, and internal forces from RFEM/RSTAB can be imported into RSECTION.
RWIND 2 is a program for generating wind loads based on CFD (Computational Fluid Dynamics). The wind flow numerical simulation is generated around any building, including irregular or unique geometry types, to determine the wind loads on surfaces and members. RWIND 2 can be integrated with RFEM/RSTAB for the structural analysis and design or as a stand-alone application.
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.
Rolled sections, the most common cross‑section type in RFEM and RSTAB, can also have user‑defined parameters. To do this, select the cross‑section to be modified in the cross‑section library and click the [Parametric Input...] button.
In RFEM and RSTAB, there are various options to renumber the individual structural elements, such as nodes, lines, members, surfaces, or solids. Two options are available for renumbering: singly and automatically.