#### Further Information

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• ### Is it possible to perform fire resistance design of cross-laminated timber panels in RF‑LAMINATE?

Fire resistance design is not implemented in the RF‑LAMINATE add-on module by default.

However, you can calculate the charring rates yourself and consider them accordingly in the module. In the following example, this is explained on a simple plate.

Structural system (Figure 01):

• Span 5 m
• Plate width 2 m
• LC2 (medium) 2.5 kN/m²
• 3 layers
• S1 35 mm C24
• S2 20 mm C24
• S3 35 mm C24
The information regarding the correction factors and stiffnesses can be found in the attached file.

Factors for fire resistance:

• Charring rate ß0 = 0.65 mm/min
• Pyrolysis zone k0d0 = 7 mm
• Charring time t = 30 min
• Effective thickness def=t ß0+k0d0=30 min × 0.65 mm/min+7 mm = 26.5 mm
Remaining thickness of Layer 3 = 35 − 26.5 = 8.5 mm > 3 mm → thickness may be applied. (Figure 02)

Because of the modified layer thicknesses, a new stiffness matrix results, which is applied in RFEM for accidental combinations with the characteristic stiffness values. For the ultimate limit state, the design values are calculated here (Figure 03).
• ### Is it possible to perform a detailed analysis of connections, supports, or reinforcements of cross‑laminated timber plates in RF‑LAMINATE?

In principle, it is also possible to perform detailed analysis in RF‑LAMINATE. In the case of a very high shear distortion, for example, it can be reasonable to use orthotropic solids for modeling. The video shows a simple modeling and result evaluation of a layer structure by using solids.

A criterion, as of when is the modeling using solids useful, is the shear correction factor. Further information and other criteria can be found in the following FAQ:

• ### How can I consider the flexibility of a continuous beam with slotted dowel connections?

The easiest way to consider this is to use the RF-/JOINTS Timber Steel to Timber module. For this purpose, the module decomposes the original connection, and creates a new structural system that considers the flexibility accordingly. This is taken into account separately for load-bearing capacity, suitability for use, and exceptional.
• ### Is it possible to generate a parts list in RFEM?

New

FAQ 004345 EN

This is not possible directly in RFEM, but the RF‑/STEEL EC3 add-on module allows you to create a list of steel parts. In Details of the add-on module, you can specify whether the parts list should apply to all members or only for members to be designed. Then, you can simply carry out the calculation and the parts list will be displayed. It is also possible to export the parts list to Excel and further edit it.
• ### Where can I set the Poisson's ratio?

New

FAQ 004341 EN

The Poisson's ratio is set under the material by using the Edit Material dialog box.
• ### When displaying the result diagrams on a member (the "rib" type), there is the option to display the internal force VL. What is this value and how is it calculated?

The force VL is the longitudinal shear force between the top surface and the member. It is calculated as an integrated shear flow between the plate and the member at a particular point on the member.

For the simplified example provided here, the resulting cross-section values for the integration width of 10 cm are as follows:

• $I_y=\frac{b\times h^3}{12}=\frac{10 cm\times20 cm^3}{12}=6,666.67 cm^4$
• $S_y=h_1\times b\times((h-e_z)-\frac{h_2}2)=10 cm\times10 cm\times((20 cm-10 cm)-\frac{10 cm}2)=500 cm^3$
• $\tau=V_L=\frac{V_z\times S_y}{I_y\times b}=\frac{5.53 kN\times500 cm^3}{6,666.67 cm^4}=0.415 kN/cm=41.5 kN/m$
The integration width has been set to the total of 10 cm.

Values:
• Iy second moment of area
• Sy statical moment
• h1 height of the upper cross-section part
• h2 height of the lower cross-section part
• ez centroidal distance
• h total height
The values can be adjusted for a T-beam.
• ### How can I set as quickly as possible that the load combinations generated by the program will be calculated according to the geometrically linear analysis, for example?

New

FAQ 004331 EN

In the "Edit Load Cases and Combinations" dialog box, you can specify in the bottom right of the "Combination Expressions" tab which method of analysis should be used as the basis for the generated load combinations. By default, the linear calculation according to the geometrically linear analysis is preset for load cases and the nonlinear calculation according to the second-order analysis for load combinations.

Thus, you can quickly determine whether the load case or the load combination is calculated according to the geometrically linear, second-order, or large deformation analysis. The postcritical analysis option allows you to carry out the stability analysis according to the large deformation analysis with regard to the post-critical failure of the entire structure.

In case the model includes cable members, the calculation according to the large deformation analysis is preset in all cases.
• ### When opening an RSTAB 8 file including scissor hinges in RFEM 5, I get an error message saying that the scissor hinges could not be imported correctly. What is the reason?

New

FAQ 004320 EN

Please check the definition of the scissor hinges in the RSTAB 8 file.

To properly consider the function of the scissor hinge, the scissor hinge of the same type must be specified on the member ends of both members ‘touching’ at a node. If this is not the case, you receive the described error message.

If you have got this error message displayed when opening an RSTAB 8 file in RFEM 5, this may lead to problems in the calculation, for example, the structure becomes unstable due to incorrect hinge definition (already in RSTAB 8).

The problem should, therefore, be adjusted either already in the RSTAB 8 file or the RFEM model after import.

• ### Is it possible to copy line releases?

New

FAQ 004315 EN

Yes, that is possible. Simply select the structure to be copied. Make sure that the line releases and all released objects are also selected. Now you can create a copy with the 'Move and Copy' function.
• ### Is Dlubal Software certified according to ISO 9001, and where can I find the corresponding certificates?

New

FAQ 004295 EN

Dlubal Software GmbH is certified according to DIN EN ISO 9001:2015.

The scope includes the development, testing, sale, and support for the FEM structural analysis software.

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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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