When calculating regular structures, data input is often not complicated but time-consuming. Input automation can save valuable time. The task described in the present article is to consider the stories of a house as single construction stages. Data is entered using a C# program so that the user does not have to enter the elements of the individual floors manually.
The modal relevance factor is a result of the linear stability analysis and qualitatively describes the degree of participation of individual members in a specific mode shape.
The Construction Stages Analysis (CSA) add-on allows for the design of member, surface, and solid structures in RFEM 6 considering the specific construction stages associated with the construction process. This is important since buildings are not constructed all at once, but by gradually combining individual structural parts. The single steps in which structural elements, as well as loads, are added to the building are called construction stages, whereas the process itself is called a construction process.
Thus, the final state of the structure is available upon completion of the construction process; that is, all the construction stages. For some structures, the influence of the construction process (that is, all the individual construction stages) might be significant and it should be considered so that errors in the calculation are avoided. A general overview of the CSA add-on is given in the Knowledge Base article titled “Consideration of Construction Stages in RFEM 6”.
You can use the selection options in the printout report to receive the detail results (in short or long form) to illustrate the individual buckling modes with the relevant buckling analysis.
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.
A member's boundary conditions decisively influence the elastic critical moment for lateral-torsional buckling Mcr. The program uses a planar model with four degrees of freedom for its determination. The corresponding coefficients kz and kw can be defined individually for standard-compliant cross-sections. This allows you to describe the degrees of freedom available at both member ends due to the support conditions.
Designing vertical insulating glass requires assigning different loads on the individual layers of the entire glass unit. This occurs, for example, with simultaneous actions from wind loads and fall protection.
The additional loads from self‑weight are usually composed of several layers; for example, classic floor and ceiling layers in buildings, or road coatings for bridge constructions. When defining load definitions in RFEM and RSTAB, you can use the multi-layer load to define the individual layers with thickness and specific weight.
In RFEM, if you want to insert a tapered member with intermediate nodes into an existing model, the issue often arises how to determine the individual cross-section depths of the tapered members quickly. The "Connect Lines or Members" command comes in handy for this purpose.
An individual user‑defined workspace can increase your productivity and make your daily work easier. This is why many users take the opportunity to adjust the toolbars in RFEM and RSTAB and to create their own toolbars containing the most frequently used commands.
In order to detect the governing internal forces of a plate, a checkerboard loading is commonly used. Since it is not necessary to divide the surface into individual load segments, loading is usually carried out by means of free rectangular loads. In the case of many loads, the normal load display can become somewhat confusing.
In RF-/FOUNDATION Pro, a graphical display of the result details is available. To see them, go to Window 2.2 Governing Design Criteria after the calculation. In the interactive graphic of this window, individual design-relevant values can be displayed for each design performed.
The new "Result Beam" member type in RFEM 5 allows you to determine the load sums of individual floors easily. To do this, model a member in the relevant floor or in all floors, then specify the relevant walls as inclusive objects in the parameters of the result beam. RFEM then integrates the surface internal forces into member internal forces.
The transparency intensity of various graphic elements in the Solid Transparent Display Mode can be edited individually in the Program Options dialog box under the Graphic tab to improve the overview.
In timber design, beams are often built from several timber elements. The individual elements can be connected with glue, nails, bolts, or dowels. A glued connection is to be assumed as rigid. In the case of dowel‑type fasteners, the joint is compliant (slip joint), and the cross‑section properties of the connected elements cannot be fully applied.
In RFEM 5 and RSTAB 8, it is possible to assign nonlinearities to member hinges. In addition to the nonlinearities "Fixed if" and "Partial activity", you can select "Diagram". If you select the "Diagram" option, you have to specify the according settings for the activity of the member hinge. For the individual definition points, it is necessary to specify the abscissa and ordinate values (deformations or rotations and the according internal forces) that define the hinge.
Steel-fiber-reinforced concrete is mainly used nowadays for industrial floors or hall floors, foundation plates with low loads, basement walls, and basement floors. Since the publication in 2010 of the first guideline about steel-fiber-reinforced concrete by the German Committee for Reinforced Concrete (DAfStb), a structural engineer can use standards for the design of the steel fiber-reinforced concrete composite material, which makes the use of fiber-reinforced concrete increasingly popular in construction. This article explains the individual material parameters of steel-fiber-reinforced concrete and how to deal with these material parameters in the FEM program RFEM.
RFEM offers the following options to design a pinned end plate connection. First, there is the option in RF-JOINTS Steel - Pinned to enter the corresponding parameters quickly and easily to receive a documented analysis, including graphics. It is also possible to model such a connection individually in RFEM and then to evaluate or manually design the results. In the following example, the particularities of this modeling will be explained and the shear forces of the bolts will be compared to the corresponding results from RF-JOINTS Steel - Pinned.
Lattice towers represent typical applications in steel construction. Examples of this special type of truss structure are antenna and overhead line towers, as well as columns for wind power stations, cable cars, and supporting frame constructions. The modeling can be done individually in RFEM and RSTAB by entering various tower elements. Furthermore, you can use different copy functions and parameterized input options. However, this procedure normally requires considerable effort. It is more convenient to model such structures using prefabricated catalog elements provided by the Block Manager. These elements are automatically stored in the database during program installation. Thus, you can use tower segments, platforms, antenna brackets, cable ducts, and so on as parameterized building blocks for generating diverse tower structures.
When designing bending-resistant connections from I-beams, the connection is dissolved into the individual parts. For these basic components of a joint, there are separate formula calculators for load-bearing capacity and stiffness. In RFEM and RSTAB, frame joints can be designed using the RF-/FRAME-JOINT Pro add-on module.
According to Clause 7.3.2 (2), standard DIN EN 1992-1-1 requires: "In profiled cross‑sections like T‑beams and box girders, the minimum reinforcement should be determined for the individual parts of the section (webs, flanges)." In the case of a floor beam with a T‑section, the minimum reinforcement should be determined for both flanges and the web if the corresponding partial cross‑sections are in the tension area. Image 01 shows the division into partial cross-sections.
BIM is often used when it comes to data management in civil engineering. The individual disciplines of architecture, structural design, construction, and structural monitoring are coming closer together. Building Information Modeling makes this possible.. Dlubal Software provides a wide range of formats for data exchange. The following article explains the details of the interface with Autodesk Revit and, in particular, the export settings.
Part 2.2 of the article series about the COM interface describes creating and modifying nodal supports, loads, load cases, load combinations, and result combinations on an example of a member. The fourth part explains creating individual tools.
RFEM and RSTAB provides two different methods for the superposition of load cases. Using load combinations, the loads of individual load cases are superimposed and calculated in a "big load case". On the other hand, result combinations only combine the results of the individual load cases. This article describes the with the basis of defining result combinations and explain it in detail on two examples.
If intersections created in RFEM 4 are opened in an RFEM 5 file, the file management of intersections remains in the old format for compatibility reasons. Thus, the individual partial surfaces of the intersection can be activated or deactivated using only the "Integrated/Components" tab, all partial surfaces can only have the same thickness, and it is impossible to use the separate FE mesh refinement for the individual surface components.
By clicking "Options" → "Display Properties" → "Edit", you can change and save display settings for printout reports and your screen. For example, you can set individual colors for cross‑sections.
SHAPE‑THIN cross‑section properties software provides the option to combine cross‑section parts in a "section" and display the cross‑section properties. Thus, you can determine the values of the individual components in a composite cross‑section.