"Distribution of load" represents a load actually applied to the system of FE mesh points or FE surfaces. The FE mesh size plays an important role in the loading in the case of line loads and free loads in particular.
In RFEM and RSTAB, you can create nodes not only by means of coordinates, but also by means of existing nodes. You can use the "Node Between Two Points" function to create a node located on an imaginary line connecting two nodes. You can enter the distance as a percentage or according to the relative lengths.
The equivalent loads determined in RF-TENDON due to prestress are transferred in RFEM as member loads or as line loads. A member load is used for member types with their own stiffness; a line load is used for member types without their own stiffness. In order to understand which values of the concentrated loads are to be transferred from RF‑TENDON to RFEM, you should use the following display settings: ~ Reference of the loads to the global coordinate system (GCS), ~ Load display: "Point"
During the cooperation between the structural and design engineers, the DXF format is often used if there is no direct interface. However, the geometrical data of these DXF files are not always accurate. For example, an inaccuracy in the third decimal place is not noticeable, but it can lead to numerical problems when generating the FE mesh in RFEM.
For the reduction of loads generated in RF‑MOVE Surfaces, you can consider the influence surfaces of a selected point. The influence surfaces are determined by RF-INFLUENCE. This procedure is useful in cases where only unfavorably acting loads should be considered. Depending on the unfavorable action, you should select the positive or negative direction.
It is often necessary to adjust the FE mesh of surface elements to the geometric structure. RFEM provides various options for this. For example, the FE axis can be rotated around a point, aligned in the direction of a point, or oriented to a user-defined coordinate system. Another option is the direction parallel to a line, and in this case in particular, it is possible to enter or select several lines.
In RF-CONCRETE Surfaces, you can use the "Filter Points" function when evaluating results by points. This filter function allows for a user-defined group of points that can be defined in the result window. You can select the filter in Window 2.3 Required Reinforcement by Points, among others.
You can document the results of RF‑CONCRETE Surfaces graphically in the printout report. To do this, the "Values on Surfaces" setting is often selected in the Results Navigator of RF‑CONCRETE Surfaces. A text bubble including a result value is displayed, and depending on the settings in the Results Navigator, it can be displayed on the surface grid points, manually defined points, or in FE mesh points.
In RFEM, you can display the result values of surfaces (from RF‑CONCRETE Surfaces, for example), which can specify the required reinforcement of the designed surfaces in grid points. Generally, the result values are initially displayed for all surfaces designed.
In RFEM, you can use the export function to export the generated FE mesh in DXF as a result. To do this, open the export dialog box in the program and select "ASCII Format - Results". In addition to a result (for example, isolines), you can select the FE Mesh in the "Results - Isolines (.dxf)" tab. After the export, the mesh in DXF is available in the DL‑FE‑MESH layer.
In RFEM, there are a file‑based and a direct DXF interface. The file-based DXF interface allows you to export the data in a DXF file that is transferred directly into an open AutoCAD file. In the interface dialog box, you can select which data are to be exported (results as isolines, result values, or finite element mesh with boundary and integration lines).
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).
In the DYNAM Pro add‑on module for RSTAB, you can now neglect masses that may have a negative effect on the equivalent mass factor when calculating eigenvalues. To do this, you can disable the masses under [Details]. These include primarily mass points located in the support of the structures.
The form-finding process in RF-FORM-FINDING displaces the corner nodes of FE elements of a membrane surface in space until the defined surface stress is in equilibrium with the boundary conditions. This displacement is independent of the element geometry. In the case of elements with four corner nodes, the free displacement may cause spatial drilling in the element plane and thus exceed the validity limits of the calculation; therefore, triangular elements are generally recommended for form‑finding systems. Triangular elements remain independent of the corner node displacement and stay within the calculation limitations.
The transparency of the glass material should not be missing in any building. In addition to the typical application areas such as windows, this building material is increasingly being used for facades, canopies, or even as bracing of stairways. Of course, the planning architects often set a very high standard of transparency on fixation of the glass panes. This requires special glass fittings that couple the glass panes.
The DXF interface in RFEM now exports a 3DFACE element in the DXF file for each FE mesh cell of the exported structure. The 3DFACE element is detected by AutoCAD during import, for example, and can be displayed as a surface in the graphic. Different visual styles help display the 3DFACE surfaces in a desired view.
If you want to connect members tangentially to a curved member or a curved surface in RFEM, it is necessary to define the member rotation of the connected members. In order to avoid manual determination, you can display the center point of the curved line and place a node on it. Then, you can select the "Member Rotation via Help node" option and specify the relevant help nodes. Thus, the members are rotated automatically in the defined plane (x-z in our example) and the top edge of the rotated cross-section is parallel to the tangent of the curved line.
Nodal supports are usually defined with regard to the global axis system. However, it is sometimes necessary to rotate the nodal support. For example, for a floor slab with a pile foundation. For geological reasons, the piles do not rest in the ground vertically, but in an inclined position. Each end point of the piles has a nodal support that can only absorb forces along the pile foundation direction. Therefore, rotating the nodal support is required. Various options for this are described in previous posts.
As mentioned in Part 1, according to the current standard DIN 18008-3, it is allowed in glass construction to represent point supports for glass components by means of FEM in order to design the adequate ultimate limit state. The rules are described in Annex B of the standard [1].