In addition to our technical support (e.g. via chat), you’ll find resources on our website that may help you with your design using Dlubal Software.
Frequently Asked Questions (FAQ)
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The described effect is not a display error, but only a question of perspective and a good example of an optical illusion. It depends on whether you perceive the representation of the axis system as an inner or outer corner.
Example: Rubik's Cube in Isometric View
The yellow side of the cube is the top surface. In the preset isometric view, you can see the inner corner of the coordinate system diagonally from above. If you simply turn the view upside down, so that Z points upwards, X to the right, and Y to the left, you can look at the bottom side of the cube, that is from above on the lower outer corner of the coordinate system.
If you rotate the view by 45 ° about the horizontal axis, you may get the impression that you look at the inner corner of the coordinate system. However, this is the outer corner.
AnswerThe working directory is a local path where the data of the currently opened structure is temporarily handled and saved. It consists of the first letters of the file. Only ASCII characters may be used.The non-ASCII characters are, for example, "ä," "ö," and "ß."To avoid this problem, replace the special characters in the file name by the ASCII characters, such as "ae" and "ss" instead of "ä" and "ß." When you open the file again, the message will no longer appear.
AnswerIf a real computer with the Windows operating system is actually used and no hardware changes and/or new installation of the operating system has been made, the license problem is usually caused by the following points:
- The mandatory service 'Sentinel LDK License Manager' may be damaged after a Windows update.
- The antivirus program blocks the file hasplms.exe.
- Other security software (e.g. Sandboxie) prevents proper communication of the license service.
It is possible to display or calculate the stresses in RFEM as well as in the add-on module by means of the following smoothing options:
- Constant on elements
- Not continuous
- Continuous within surfaces
- Continuous total
- Continuously by groups or Continuous by groups
To compare the results, the same display type and calculation type must be selected in RFEM and RF-STEEL Surfaces.
In RFEM, it is possible to do this in the Project Navigator Show → Results → Surfaces → Distribution of Internal Forces/Stresses (Figure 02). In RF-STEEL Surfaces, this can be displayed or changed in the Details → 'Options' tab (Figure 03).
AnswerIt is caused by the automatic orientation of the local axes in relation to the global axis system. In most cases, it is sufficient to specify a member rotation using an angle or a help node. However, if the inclination of the member is reversed, it must be divided and then adjusted utilizing the member rotation.You can find a detailed description of the member rotation angle in RSTAB and RFEM in the links below.
AnswerThe default definition of surface elements assumes an isotropic material behavior. The load attempts to get to the supports as quickly as possible. The stiffness of the elements also plays a role here.
For plates, the structural behavior or the load transfer is best represented and understood with the trajectories of the principal moments αb. For wall elements, it is necessary to consider the trajectories of the principal axial forces αm.
In this example, the load is not applied parallel to the free plate´s edges but almost perpendicular to the supports, because this is the shortest path of the load transfer.
At the blunt corners of the system, the load absorption area is larger than in the support centers, corresponds to a singularity point and has -as a consequence of that- large peak values.
In order to force the system to remove the load parallel to free plate edges, the following procedure is the fastest:
Definition of an orthotropic plate. It is recommended to use the orthotropy type 'Effective Thicknesses'. The effective plate thickness has to be specified in the support direction and a very small thickness (e.g. 1mm) in the secondary support effect.
The second graphic shows the difference between both models.
AnswerDuring the development of the FRAME-JOINT Pro add on module, the lower end plate overhang was fixed because it results in an improved load transfer of the compression force into the column.
It is not possible to deactivate the overhang and its minimum dimension is defined as follows:
uu = max
- End plate thickness
- √2 * bottom flange weld
- for end plate depths < 200 mm → min 10 mm
- for end plate depths > 200 <400 mm → min 20 mm
- for end plate depths > 400 → min 30 mm
AnswerFrom the formula of EC 3-1-8, it is obvious that the ultimate tension forces of the beam's end plate are introduced into the column flange and thus directly into the column web.
Therefore, the upper end plate is not fully stressed by these forces.
For purely structural reasons, the column end plate is available for the stiffening and the panel boundary and serves for the transmission of the proportional force flowing into the stiffener in case of a required diagonal stiffener.
If the beam and the surface share the same plane, they are firmly connected to each other.
Although the member end has a member end hinge, it is already rigidly connected to the surface in the next FE element and shares the load transfer with the surface by means of bending. To avoid restraining moments, the surface must also have a line hinge.
AnswerThere can be several reasons for this.
- It may i.a. be caused by the fact that the DXF file contains only blocks that have first to be separated e.g. by means of the ‘Explode’ function .
- Another source of problems may consist in the fact that a specific layer is selected for import in the ‘DXF ASCII Formats’ tab of the RFEM or RSTAB import dialog box that either does not exist or contains no data.
- The type of backup in the CAD program may also cause some problems. It is possible to save DXF files in the binary DXF format. Their advantage consists in saving about 25% of the memory size. However, they cannot be processed by RFEM and RSTAB. Therefore, to save the DXF file, the ASCII format should be selected in the CAD program.
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If not, contact us via our free e-mail, chat, or forum support, or send us your question via the online form.
Wind Simulation & Wind Load Generation
With the stand-alone program RWIND Simulation, wind flows around simple or complex structures can be simulated by means of a digital wind tunnel.
The generated wind loads acting on these objects can be imported to RFEM or RSTAB.
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