In many frame and truss structures, it is no longer sufficient to use a simple member. You often have to consider cross-section weakenings or openings in solid beams. In such cases, you can use the "Surface Model" member type. It can be integrated into the model like any other member and offers all the options of a surface model. The present technical article shows the application of such a member in an existing structural system and describes the integration of member openings.
The goal of using the RFEM 6 and Blender with the Bullet Constraints Builder add-on is to obtain a graphical representation of the collapse of a model based on real data of physical properties. RFEM 6 serves as the source of geometry and data for the simulation. This is another example of why it is important to maintain our programs as so-called BIM Open, in order to achieve collaboration across software domains.
A new capability within RFEM 6 when designing concrete columns is being able to generate the moment interaction diagram according to the ACI 318-19 [1]. When designing reinforced concrete members, the moment interaction diagram is an essential tool. The moment interaction diagram represents the relationship between the bending moment and axial force at any given point along a reinforced member. Valuable information is shown visually like strength and how the concrete behaves under different loading conditions.
A standard scenario in timber member construction is the ability to connect smaller members by means of bearing on a larger girder member. Additionally, member end conditions may include a similar situation where the beam is bearing on a support type. In either scenario, the beam must be designed to consider the bearing capacity perpendicular to the grain according to NDS 2018 Sec. 3.10.2 and CSA O86:19 Clauses 6.5.6 and 7.5.9. In general structural design software, it is typically not possible to carry out this full design check, as the bearing area is unknown. However, in the new generation RFEM 6 and Timber Design add-on, the added "design supports" feature now allows users to comply with the NDS and CSA bearing perpendicular to the grain design checks.
If members aligned in space meet in a node, the local x- or y-axes of the members do not lie in one plane, since the local z-axes are aligned in the plane of gravity.
RFEM and RSTAB offer many display options in the Display Navigator. They can be completely different, depending on their function. You often have to click several times to make certain changes. If you want to optimize your work, you can create user‑defined views. In these views, you can save all specified settings. The following example illustrates this principle.
In the RF-GLASS add-on module, 3D rendering is implemented to facilitate the definition of the support conditions. This interactive graphical visualization facilitates the input and control of line and nodal supports. However, the schematic display can also be selected, if necessary.
You can color the surfaces in the direction of the local z‑axis using the indicated option in the Display Navigator. By default, the side lying in the negative z-direction is colored red and the side lying in the positive z-direction is colored blue.
In RFEM and RSTAB, you can now also display and check the types of members used visually, by means of colors. To do this, an option has been integrated into the Display Navigator.
For a clearer display of the structure, you can display it in different colors. The corresponding selection can be opened by right-clicking the work window.
In RF‑/FOUNDATION Pro, the reinforcement to be placed in the foundation slab and, if necessary, the bucket links, is displayed in a 3D rendering and in the reinforcement drawings.
In RFEM and RSTAB, you can analyze members with a variable cross-section, which can also consist of freely defined SHAPE-THIN cross-sections. The cross-section properties are interpolated in order to determine the internal forces and deformations.
The calculation of structures based on digital twins is becoming an everyday task in the engineering office. If a digital building model already exists, you want to continue to use the information contained in it as seamlessly as possible. This places far-reaching demands on modeling and interfaces for BIM-compatible structural analysis software.
In spatial structures, the member position plays an important role in terms of determining internal forces. The orientation of member axes can be defined either by a global cross-section rotation angle, or by a specific member rotation angle. These two angles are added to determine the position of the main axes of a member in a 3D model.
You can now use axial expansion joints in RF‑PIPING. These are applied to absorb movements of extension and compression in the axis direction due to the thermal expansions of the piping.
The new options for the graphical display of reinforcements that were implemented in RF‑CONCRETE Members and CONCRETE are now also available in RF‑/CONCRETE Columns.
In CONCRETE and RF‑CONCRETE Members, you can open a dialog box with a 3D rendering of the existing reinforcement in Window 3.1 or 3.2. Now, you can also display different reinforcement views in several dialog boxes at the same time. The "Isometric and 3 Views" option known from RFEM is available here as well.
When modeling arc-shaped members, the problem shown in the figure may occur. It seems as if the member cross‑section is twisted or the load applied on the local z‑axis changes direction. How does this come about?