#### Further Information

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• ### Why is the material property in the program different from the material property in the current standard?

New

FAQ 004366 EN

The reason for this is that the program allows you to select the materials from valid as well as from old ("invalid") standards.

In the program, the materials are stored with the material description and the standard. When selecting the desired material, it is necessary to pay attention to the material description and the standard to ensure that the selection is correct.

• ### In RF-FOUNDATION Pro, I receive error message No. 30195. What can I do?

The error message indicates that no option was found to define the required reinforcement for the mats and rebars selected from you.
After clicking OK, you will automatically be redirected to Window 1.3. Here, please select additional mats and/or rebars and then perform the design again.
• ### How can the vertical fingers be considered for a glued laminated beam?

In the main program RFEM/RSTAB, a member rotation of 90° is first required so that the lamellae of the glued-laminated beam are arranged on edge, see Figure 1.

To also consider the on-edge position of the beam in the design in the RF-/TIMBER Pro add-on module, increase the resistance for edgewise bending within the parameters set in the National Annex in the tab 'Other Settings 2/2', see Figure 2.

• ### RF-STEEL AISC add-module shows non-designable results for general cross-sections because of shear buckling checks according to Chapter G. How do I solve this?

When designing general cross-sections in the RF-STEEL AISC module, a "Non-designable" message is given for the design ratio. General cross-sections are defined in the program as user-defined sections or shapes which are not included in the specification. Though, some user-defined cross-sections can be designed under specific conditions. The warning message is displayed because shear buckling is not provided for general cross-section in the AISC 360-16 [1] Chapter G. More info on this topic can be found in the RF-STEEL AISC manual linked below.

This warning can be turned off in RF-STEEL AISC add-on module under the "Details" button > Shear Buckling > "Shear buckling warning for general cross-section."

• ### I have used the RF-/DYNAM Pro add-on module to generate the governing result combinations of seismic loads. What is the next way to perform a design of the individual components?

With the Equivalent Loads and Forced Vibrations add-on modules, you can create result combinations that contain the governing combinations of seismic loads. To perform a design with them, they have to be combined further on the basis of the extraordinary combination. This combination is defined, for example, in EN 1990 Art. 6.4.3.4:

${\mathrm E}_{\mathrm d}\;=\;\underset{}{\sum_{}^{}\;{\mathrm G}_{\mathrm k,\mathrm j}\;+\;\mathrm P\;+\;{\mathrm A}_{\mathrm{Ed}}\;+\;}\overset{}{\underset{}{\sum{\mathrm\psi}_{2,\mathrm i}\;{\mathrm Q}_{\mathrm k,\mathrm i}}}$

This accidental combination has to be defined manually in RFEM. Make sure that (for a direction combination with the 100/30% rule), both created result combinations from RF-/DYNAM Pro have to be added with the "Or" condition. A combination like this is displayed in Figure 02.

This accidental combination can then be used for further design. It is possible to evaluate the governing internal forces as well as to import and calculate this combination in the design modules.
• ### When calculating an RF-/JOINTS Steel - Column Base case, I get the message No. 48335 saying that the bending moment Mz exceeds 5% of the plastic moment resistance. What does it mean?

The analysis of a rigid column footing is performed according to EN 1993-1-8 in the RF-/JOINTS Steel - Column Base add-on module. The standard only provides for simple bending in the design format. The design can be performed for compression only, tension, simple bending, or a combination of bending and tension, or bending and compression. If the note is confirmed with 'Yes', the add-on module performs all designs neglecting the unsupported internal force Mz.
• ### Why is the shear stiffness reduced to 10% in the RF‑LAMINATE add-on module as well as for the orthotropic material model in RFEM for the shear modulus Gyz? I think the shear stiffness in the shear plane Gxy would have to be reduced here?

The reduction of the shear stiffness is caused by the fact that the fibers perpendicular to each other have a very small stiffness and a low strength. For this reason, the rolling shear strength of CLT panels is also very small.

In the case of cross-laminated timber plates, the glued sideboards are assumed on the boards. The boards are applied in the longitudinal direction along the x‑axis of the coordinate system (Figure 02). For the shear stresses in Figure 02, the shear stress τyz is thus opposed to the rolling shear strength.

The same applies to the shear stiffnesses. In the direction of the minor axis (yz‑ plane), the stiffness of the individual boards is considerably smaller than in the direction of the principal axis (xz‑plane) and also larger than in the xy‑plane. The coordinate system shown in Figure 02 should be placed on the boards in Figure 03.

• ### Which method of analysis is used for insulating glass?

FAQ 003330 EN

If there is an insulated glass unit selected for the design in RF‑GLASS, the method of the large deformation analysis is set by default. Based on the existing gas volume in the space between glass panes, this method of analysis is also required and cannot be changed.

• ### Does Dlubal Software provide any solution for composite bridge construction, or perhaps also verification examples or reference objects?

Unfortunately, we do not currently have any solutions for the design of composite bridges in the program. Therefore, there are no verification or reference projects available for this.

Basically, you can create the models of composite bridges made of steel and concrete in RFEM 5 and use them for the determination of internal forces, for example. However, we are currently unable to offer any solutions for the design of such bridges according to the relevant standards.
• ### When determining the effective cross-section properties according to EN 1993‑1‑1, EN 1993‑1‑5, or EN 1999̩1‑1, SHAPE‑THIN displays a warning message saying that the effective widths are only determined for straight elements. What does it mean?

The cross-section class is defined according to EN 1993‑1‑1 and EN 1999‑1‑1 by the maximum width/width ratio c/t or b/t of the cross-section parts subjected to compression. EN 1993‑1‑1 or EN 1999‑1‑1 only cover various straight c/t or b/t parts. Therefore, the classification and determination of effective widths is not possible for the curved c/t or b/t sections.

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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.

#### First Steps

We provide hints and tips to help you get started with the main programs RFEM and RSTAB.

#### 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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