#### Further Information

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.

Receive information including news, useful tips, scheduled events, special offers, and vouchers on a regular basis.

• ### What do the 9 points refer to when considering any cross-section (z-section) in the RF-/STEEL Warping Torsion?

New FAQ 003205 EN-US

The setting of the load application in the Details refers to the principal axes of the respective cross-section. For a Z-profile as an example, a box with the 9 edge nodes is put around the profile. The load application is then always related to the rotated principal axis angle and the corresponding eccentricities.

• ### I would like to connect a column rigidly to the beam flange. However, in the RF-/JOINTS Steel - Rigid add-on module, the beams are always connected to the column flange. How can I create a continuous beam?

New FAQ 003182 EN-US

The geometry depends on the definition of the structural components. In the "1.2 Nodes and Members" window, you determine, which member belongs to a column and which to a beam. In the default case, the program always recognizes the column as continuous structural component (see Figure 01). In order to make the beam continuous, you simply have to change the status of the individual members (see Figure 02). The given beam will be assigned the “Column” status and the given column will be defined as a “Beam”.

• ### Instead of displaying the results in the STEEL-EC3 add-on module, the message "Write Data () failed of module RF-STEEL EC3" appears. What is the error?

New FAQ 003168 EN-US

This is a bug that occurred in version 5.10. It has been fixed in current versions. The error was caused by a Windows update that set automatic delete of temporary files and folders. The program has created a folder to store temporary files or calculated results. Unfortunately, before the calculation ran out, Windows deleted the folder. The program had nowhere to store the data and displayed a message: "Write Data () failed of module RF-STEEL EC3". Unfortunately, no data can be saved. To resolve this issue, disable the Windows "Temporary Unused Erase Feature" or install a newer version of RFEM.

• ### When calculating a connection with the FRAME-JOINT Pro add-on module, a message appears stating that the value is out the allowable range (provisional value: 160, minimum value 200). What does the mentioned note mean?

New FAQ 003159 EN-US

It is often the case that the member dimensions do not match.
In the example model, the beam has a flange width of 200 mm and the column support of 160 mm.

This joint is not allowed in the add-on module because the flange width of the column should be at least as large as the flange width of the structural element to be connected. As soon as the cross-sections are defined according to this rule, the connection design is also satisfactory.

• ### When carrying out the fatigue design, I am getting very little or no utilization of my members.What is the reason for this?

New FAQ 003151 EN-US

The RF-STEEL Fatigue Members add-on module requires a stress cycle or a stress range for the fatigue analysis.

To be able to determine them, the input of the load cases to be designed has to be checked.

For example, if only the load cases with the actual operating load have been entered for the design and the self-weight of the structure (here e.g. LC1) was not selected, this effect may occur.

If the load case "Self-Weight" is used for the calculation of the stress cycle, a much higher utilisation may result.

In this context, reference should also be made to result combinations selected for the design, if applicable. They should also be created so that the governing stress cycle in the module can be determined.

• ### I perform a stability analysis according to the second-order analysis. Why is the partial safety factor γM1 used for a stress analysis in this case?

New FAQ 003149 EN-US

For cross-section and stability designs, the Eurocode provides for different partial safety factors. It is important to note if stability analyzes are carried out by applying the second-order analysis and applying imperfections as cross-section designs. In this case, reduce the resistances with γM1.

New FAQ 003127 EN-US

The standard 1993-1-8 specifies, which kind of cross-sections can be considered. The designs are interpreted in such a way that only one wall thickness is possible per cross-section. If an invalid cross-section is detected, a corresponding message is displayed (see Figure 1). Therefore, the question about the extension for such cross-sections should be answered in the negative. The standard is largely based on tests/research. Therefore, the focus is on hot-formed hollow sections according to EN 10210 and cold-formed hollow sections according to EN 10219.

• ### When calculating a cable with the STEEL EC3 add-on module, I receive the error message “Incorrect characteristic stresses for material No. 1! Please correct this in Window 1.2.”

New FAQ 003110 EN-US

For the “Cable ...” material, there are no specifications for yield strength and tension capabilities stored in the database (see Figure 2). Therefore, the add-on module for these members is missing the calculation basis. For being able to design such materials, it would be necessary to create own material and, if the manufacturer information is known, add the missing parameters manually.

• ### How do I combine the effect of the wind load on a cable-tightened pylon which consists of a mean wind load and additional field loading (patch load) according to the standard EN 1993-3-1 B.4.3.2.5 (1)?

New FAQ 003104 EN-US

In Chapter B.4.3, the standard EN 1993-3-1 describes an equivalent load method to consider the dynamic response to the turbulence of the natural wind.

[1] To determine the effect of the wind load STM , the internal forces Sm from the mean wind load are combined with the structural response Sp depending on the zone-specific additional loads.

${\mathrm S}_{\mathrm{TM}}={\mathrm S}_{\mathrm m\;}\pm{\mathrm S}_{\mathrm p}$

[2] Due to the nonlinear structural behavior, the patch loads have to be analyzed together with the mean wind load in the patch load cases Si. Here, you have to analyze the selected patch with the increased patch load and the remaining zone with the mean wind load. In order to determine the pure fluctuation components of the increased field-wise additional load to the mean wind load, subtract the mean wind load Sm from the patch load cases Si. The structural response Sp is then obtained from the root mean square value of the mentioned difference.

${\mathrm S}_{\mathrm p}=\sqrt{\sum_{\mathrm i=1}^{\mathrm N}\left({\mathrm S}_{\mathrm i}-{\mathrm S}_{\mathrm m}\right)^2}$

where
i ... Number of considered fields
N ... total number of required load cases (considered fields i)
Sm ... internal forces due to mean wind load
Si ... internal forces due to i-th load case (mean wind load with partially increased patch loads)

• ### I have entered a 2D frame and would like to provide the ridge with a lateral and torsional restraint. Do I have to enter an intermediate support or a nodal support in RF- / STEEL EC3?

New FAQ 003084 EN-US

You can either define the nodal support or the intermediate restraint in RF- / STEEL EC3.

If you already have nodes in your actual RFEM or RSTAB model, we recommend directly entering the nodal support in the 1.7 dialog box, because you can select the nodes directly in the model. See Figure 01.

If you want to consider intermediate storage at a point in a horizontal beam where you do not have a node available in your actual system, you can use the intermediate support and select the intermediate support (for example Preload (lateral / torsional restraint)). See Figure 02.

1 - 10 of 74