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)
Customer Support 24/7
AnswerIn order for smoothing ranges to be considered in the design in RF-STEEL Surfaces, they must always be activated in the detail settings of the add-on module. See Figure 01 with the detail settings in RF-STEEL Surfaces.
AnswerIn RF-/JOINTS Steel - Rigid, the design according to EN 1993-1-8 Chapter 6.2.7 Equation 6.24 is implemented. If the acting axial force exceeds 5% of the plastic resistance N pl, Rd , Equation 6.24 is used.
You can find this setting in the 'Details' of the 'Fire Resistance' tab.You can also control the time of fire resistance individually for each member or set of members.Subsequently, it is possible to find the input in Table 1.10 for the members or 1.11 for the sets of members.
AnswerDuring the development of the FRAME-JOINT Pro add on module, the lower end plate extension was fixed because it results in an improved load transfer of the compressive force into the column.
It is not possible to deactivate the extension 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
AnswerIn the RF-/STEEL add-on module, an equivalent stress design is performed according to von Mises. An elastic stress design (EL-EL) is to be made. In RF-/STEEL EC3, a classification is carried out before the design. If the cross-section is classified as class 1 or class 2, the design is performed against plastic limit internal forces. An EL-PL design is performed. If you do not want to use the plastic load reserves, you can switch the design to EL-EL in the details of the RF-/STEEL EC3 add-on module. The results are then comparable with RF-/STEEL.
AnswerThe internal forces and deformations are determined according to the second-order analysis for flexural-torsional buckling taking into account 7 degrees of freedom. For a linear calculation of deformations, a vertical/horizontal load results in only one vertical/horizontal deformation. Since the internal forces refer to the deformed system and it is a nonlinear analysis, this is not valid for the second-order analysis for flexural-torsional buckling.
The deformations in the shear center can be checked in RSTAB and RFEM with the RF-/FE-LTB add-on module (see Figure 02). The deformations that additionally result from the displacements or rotations can only be controlled with a surface model in RFEM.
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.
You can control the detail categories in the input dialog box "1.3 Cross-Section" and in the "Edit Detail Categories" dialog box.The specified standard values can be selected here. Unfortunately, it is not possible to manually adjust these values.
AnswerIn CRANEWAY the internal forces are typically displayed only for max and min locations. If you want to get each internal force on each x-location, then you have to run the detailed calculation and to disable the option "Show only governing results". How to do it, we show you in the short video.
Most likely, the error is in the selection of the cross section:
For a steel design, a thin-walled flat steel cross-section should be selected instead of a rectangular solid cross-section, see Figure 1.
The reason for the high shear stress of a solid cross-section is caused by the existing stress points of the cross-section or by the corresponding thickness of this stress point.
In the case of a thin-walled flat steel cross-section, there are four stress points at the corner points of the cross-section with the corresponding thickness t = 10 mm, see Figure 2.
For a solid cross-section, however, there is another stress point in the center, where the maximum of height h or width b is assumed as the thickness t for this cross-section type. In this case, the width b is 200 mm, see Figure 3.
This results in a small torsional section modulus Wt and a correspondingly high shear stress.
Therefore, the solution is, as described above, to select flat steel within the main program.
Did you find your question?
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.
Your support is by far the best
“Thank you very much for the useful information.
I would like to pay a compliment to your support team. I am always impressed how quickly and professionally the questions are answered. In the industry of structural analysis, I use several software including service contract, but your support is by far the best.”