This article describes and explains the influence of bending stiffness of cables on their internal forces. Furthermore, the text provides information on how this influence can be reduced.
Lateral-Torsional Buckling (LTB) is a phenomenon that occurs when a beam or structural member is subjected to bending and the compression flange is not sufficiently supported laterally. This leads to a combination of lateral displacement and twisting. It is a critical consideration in the design of structural elements, especially in slender beams and girders.
The ASCE 7-22 Standard [1], Sect. 12.9.1.6 specifies when P-delta effects should be considered when running a modal response spectrum analysis for seismic design. In the NBC 2020 [2], Sent. 4.1.8.3.8.c gives only a short requirement that sway effects due to the interaction of gravity loads with the deformed structure should be considered. Therefore, there may be situations where second-order effects, also known as P-delta, must be considered when carrying out a seismic analysis.
In RF-/DYNAM Pro, you can now keep the existing results. For example, if you work with several dynamic load cases, you can calculate or modify the individual dynamic load cases while retaining the unchanged results of the other dynamic load cases.
RWIND 2 and RFEM 6 can now be used to calculate wind loads from experimentally measured wind pressures on surfaces. Basically, two interpolation methods are available to distribute pressures measured in isolated points across the surfaces. The desired pressure distribution can be achieved using the appropriate method and parameter settings.
Using the Timber Design add-on, timber column design is possible according to the 2018 NDS standard ASD method. Accurately calculating timber member compressive capacity and adjustment factors is important for safety considerations and design. The following article will verify the maximum critical buckling strength calculated by the Timber Design add-on using step-by-step analytical equations as per the NDS 2018 standard including the compressive adjustment factors, adjusted compressive design value, and final design ratio.
The national parameters of EN 1992‑1‑1 for each country can be exported from RF‑/CONCRETE, RF‑/CONCRETE Columns, and RF‑/FOUNDATION Pro. To do this, there are interfaces with MS Excel, OpenOffice, and CSV. By exporting the national parameters, you can edit them in (for example) MS Excel, and display possible differences between the individual National Annexes clearly (see the image).
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.
When modeling structural systems or loads, input errors or faulty objects may occur due to subsequent modifications, displacements, and adjustments in the model.
With the introduction of OSG graphics for the representation of design reinforcement in RF‑CONCRETE Members and CONCRETE, you can also select the reinforcement position directly in the graphic. Right-click the mouse to open the context menu where you can edit, copy, or delete the selected reinforcement position.
For situations where no design is available, RF-/STEEL EC3 provides the option to neglect the respective internal forces. Examples of such situations are: bending and compression on angle sections, multi-axial bending for the design according to the General Method, torsion.
The updated Results Navigator of RF‑JOINTS allows you to display the results of different module cases simultaneously. Thus, you can display all column base designs at the same time in order to perform collision checks of the foundations, for example.
A modell check allows you to find overlapping members, among other things. However, this targeted selection could cause some minor problems. Therefore, there is a selection window now available, which appears when you click on one of the elements. This appears by clicking on one of the elements. Additional information helps you to select the correct member.
You may already be familiar with the "Center of Gravity and Info" function, which can be accessed using the shortcut menu of any element. If you want to display this information on several elements consecutively, you have to close the dialog box and open the shortcut menu of the next element over and over again.
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.
In RFEM, if you want to display a curved geometry (preferably in one continuous line), you can use splines or NURBS, for example. When modeling, you should pick the individual nodes one after another. If a mistake is made, you can go back using the special Undo function in the "New Spline Line" window. Thus, it is not necessary to enter the entire continuous line again.
With the "Info About Object..." function available in the menu under "Tools", you can display all the information about an object by placing the cursor on it in the graphical window.
CFD calculations are in general very complex. An accurate calculation of wind flow around complicated structures is very demanding on time and computational costs. In many civil engineering applications, high accuracy is not needed and our CFD program RWIND 2 enables in such cases to simplify the model of a structure and reduce the costs significantly. In this article, some questions about the simplification are answered.
The geometry data of an RFEM model are currently managed in 29 tables, so not all of the tabs are displayed at once. To open a particular table, we recommend using the navigation menu that you can open by right-clicking on any tab. A shortcut menu appears, where you can quickly access the desired input table.
Click the [Details] button in RF-GLASS to select the results to be displayed. In order to get a better overview for the result evaluation, you can select the individual stress graphics (principal stresses, stresses oriented to axes, shear stresses) as well as various result windows. This way, you can show only the results you require.
The steady state for periodically excited structures can be determined by means of the modal analysis in the DYNAM Pro – Forced Vibrations add-on module. This is an advantage if only the structure's steady state is of interest. Instead of a complete solution of the equation of motion, only a special solution is displayed.
In order to meet the requirements for the parameters of special buildings modified according to standard adjustments, you can create new National Annexes from an existing one. To do this, copy the National Annex and adjust the parameters to the requirements.
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.
Surfaces can be created using the "Surface via Line Extrusion" function by extruding lines perpendicular to the active work plane. The Video (WMV) shows how to use this function.
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.
In RF-CONCRETE Surfaces, the reinforcement areas of the mesh reinforcement for basic and additional reinforcement are not entered manually, but you can select them in the library. Therefore, various product ranges are available (for example, from Germany, Austria, and the United States).