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Frequently Asked Questions (FAQ)
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That is possible. For example, if you select "All Files" in RSTAB 7 under "Open" for the file type, RSTAB 8 files will also be visible. These can be opened.
A warning message will appear, as of course features that are not included in the older version can not be considered.
Another possibility is to rename the file from * .rs8 to * .rs7, this can also be opened directly. The warning also appears.
For RFEM, this procedure works analogously.
In an older model in RFEM 4 or RSTAB 7 I measured a DuenQ cross section or general cross section in STAHL EC3. At that time a cross-sectional class 1 or 2 was determined. I have now opened the model in RFEM 5 and now the cross section is classified only class 3 or 4. Why is that? Was the design more economical at the time?
AnswerThe dimensioning of general cross-sections or DuenQ cross-sections in STEEL EC3 is always elastic, ie after class 3 or 4. Since the interaction conditions are restricted to a few cross-sections, no plastic dimensioning is possible for any cross-sectional shapes. In RFEM 4 and RSTAB 7, however, a cross-section could still be classified as class 1 or 2, although the subsequent design took place elastically.To eliminate this ambiguity and to create consistency, the classification has also been changed to cross-sectional class 3 and 4.
It appears that the versions RFEM 5.18.01 and Halfen HDB 13.21 are not compatible.In RF-PUNCH Pro, I receive the error message saying that the design program Halfen HDB can not be found. This is installed and registered with me.What can I do?
AnswerIn fact, there is a shortcoming in the interface between Halfen HDB (version 13.21) and RF-PUNCH Pro (5.18.01). We have fixed this deficiency by updating it.You can find the download link for the update via the download area of your Dlubal Account or directly by the message of our hotline support.
The letter R in the program names RFEM and RSTAB stands for "spatial". This refers to the possibility to calculate 3D models (spatial) according to finite element method or as frame structures.
In RFEM, it is possible to open and further edit structures with loads and load cases, which has been modeled in RSTAB. This may be necessary, for example, if it is determined during the model input that it makes sense to include surface elements such as wall panes in the existing RSTAB model.
In order to open an RSTAB file in RFEM, you have to change the file type in the "Open" dialog box either to "File type RSTAB" or to "All Files." In this way, you can display not only the RFEM files, but also all RSTAB files stored in the selected directory. After opening the RSTAB file, you can save the model as an RFEM file for further editing.
However, it should be noted that the printout reports or input data already created in add-on modules cannot be transferred.
An RFEM file can be imported in RSTAB by renaming the file extension *.rf5 to *.rs8. Also in this case, all module entries and printout reports are deleted. You should also note that beam structures are only transferred in RSTAB; surface elements are deleted.
AnswerIt is possible to simulate one-way continuous slabs (e.g. precast slabs) by using the "orthotropy" of the surfaces.You can set the stiffness type "Orthotropic" in the "Edit Surface" dialog box separately for each surface. See Figure 01.In the "Edit Surface Stiffness - Orthotropic" dialog box, you can define the orthotropy type and select, for example "Effective thicknesses". See Figure 02.You can then define the effective thickness in the local x and local y-direction of the corresponding surface in the "Effective thickness" tab. Moreover, you also have the possibility in this dialog box to define an effective thickness for the self-weight. See Figure 03.
AnswerRSTAB is a 3D structural frame analysis program where the design of 2D and 3D frameworks is possible. The efficient RSTAB solver allows for linear and nonlinear calculations of internal forces, deformations, and support reactions.
With RFEM, you extend the member design by plates, shells and solids according to the Finite Element Method. These elements can be combined arbitrarily in a structure. RFEM contains almost all functions from RSTAB; that is why also pure frameworks can be designed with it.
The user interface and the handling of RSTAB and RFEM are almost identical, but RFEM offers more functions due to the greater scope of the program. The import of structure and load date from RSTAB to RFEM and vice versa is possible as long as the objects are supported by both programs.
Various add-on modules are available for structural design in RSTAB and RFEM considering both material and standard-specific requirements. Thanks to the modular software concept, it is possible to put together a program package which is adapted to the individual needs. It is possible to upgrade the program at any time.
Until RFEM 5.07.11 there was a problem with multi-core processors - eg Intel XEON.
Please exchange and try the two files attached to this FAQ on the problem computer.
Folder Program Files / Dlubal / RFEM 5.07 or Program Files / Dlubal / RFEM 5.07
The calculation does use all kernels. Some processors (Intel Core i7, i9, XEON...), however, support Hyper-Threading Technology. This means that each physically available procesor core is split up into two virtual cores for applications. This aims at a better usage of the single units of the core. There are some applications which benefit from this and run faster. However, this is not the case for the computation kernel of RFEM. Therefore, the computation kernel of RFEM often only uses the physically available cores, and Task Manager displays that the processor seems to only have a usage of 50%.
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