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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With the COM interface, you can access most operating elements as well as results of the following programs or add-on modules:
- RF- / STEEL EC3
- RF- / CONCRETE
- RX-TIMBER Glued-Laminated Beam
- RF-/TIMBER Pro
- RF- / DYNAM Pro
This is because the effective lengths or buckling lengths of members and sets of members differ. While the effective length is used for the stability analysis for members, RFEM takes the length of the summarized members for the set of members.
The frame shown in Figure 01 consists of a horizontal beam that is divided into four equally long members. In addition, a set of members is created for the four members. The stability analysis is carried out for both cases according to the equivalent member method.
For the design of members, the program calculates with a length of 1.00 m in each case. In contrast, the set of members has a length of 4.00 m (see Figure 02). This difference in length naturally affects the stability design, which means that the capacities are also different (see Figure 03).
In addition, it is not recommended to calculate all members and sets of members in a single design case because this leads to falsified results.
AnswerIn the HolzPro module, double rectangular check cross sections (H-2B cross section) can only be dimensioned with a constant cross section height over the bar length. Gevoutete H-2B cross-sections are excluded from the design. In such a case, it makes sense to depict the two rectangular cross sections as individual rectangular cross sections. Either one models the two bars geometrically separated from each other and couples them eg with rigid bars, or one activates the option "Allow double bars" in the menu item "Edit" and assigns the two bars, which are initially on top of each other, corresponding eccentricities. These bars can then be dimensioned in the add-on module HolzPro. At the bottom of the Downloads section is an example file available.
You have probably carried out the design in RF‑/TIMBER Pro according to DIN 1052:2008 and used a cut-to-grain angle of less than 3° (see Figure 01). According to Section 10.4.1 (1) of DIN 1052, such a cut-to-grain angle does not need to be considered. If you switch the design to the current DIN EN 1995 (see Figure 02), the design will also be carried out for the angle of less than 3°.
Furthermore, the module allows you to analyse transversal tension stress in the apex etc., according to the Section 6.4.3 ff. of the Eurocode. This procedure is explained in detail in the webinar.
AnswerThe deduction of the precamber in the serviceability limit state design is actually not regulated in steel structures. However, in response to customer requests, we have adopted the corresponding add-on module according to the timber or concrete add-on module. However, according to the standard specification, this value should only be considered in the quasi-permanent design combination.This does not apply to the characteristic and frequent design situation. Thus, as soon as the design situation in the add-on module is adjusted accordingly (see figure), the applied precamber is also subtracted from the resulting deformation.
AnswerIn the basic information, the rod sets must first be selected so that they can be dimensioned for the corresponding limit states. Thereafter, various requirements for the proof of serviceability can be made in the usability parameters.
I have modified cross-section properties or reduced stiffnesses of a members in RFEM/RSTAB. After a new calculation, the deformation of the structural system has adjusted itself to the new cross-section properties. However, this change is not taken into account when performing design in add-on modules.
In principle, the modified cross-section properties are not transferred into add-on modules, such as RF‑/STEEL or RF‑/STEEL EC3. They are only used for the calculation of internal forces.
In the add-on modules, stresses are calculated using the real cross-section dimensions, which cannot be modified. This would be difficult to implement as many designs require the element width or height and due to the modification, it is not known which parameter has been reduced exactly. This is important for the c/t-designs in RF‑/STEEL EC3, for example.
AnswerThe affected cross-section is shown in blue. This means that in RSTAB / RFEM a different cross section is used than in the additional module. This in turn means that the internal forces with the cross-section assigned in RSTAB / RFEM (in Fig. 1 = IPE 300) and the proof in the additional module with the cross-section assigned there (in Fig. 1 = IPE 80). Either this was changed manually in the additional module or a cross-section optimization was carried out.It is therefore recommended to use the right mouse button to copy the cross-section from RSTAB / RFEM (see Figure 2) or to pass the cross-section used in the add-on module to RSTAB / RFEM. The cross sections are then identical again or shown in black letters.
Yes, it is possible. For reasonable predimensioning of cross-sections in RF‑/TIMBER Pro, you can optimize any cross-section of the relevant cross-section serie.
In the case of a local dongle, you can activate the new add-on module very quickly using the authorization file.
We provide you this file immediately after your purchase via e-mail or our extranet.
If you use a network dongle, the only thing you need to do is to write the new information in it.
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