#### 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 is the formula used to calculate the ASCE 7 wind velocity profile?

The wind velocity profile in RWIND Simulation according to the ASCE 7-16 standard [1] is calculated based on Eq. 26.10-1. The coefficients and basic wind speed in this equation below are incorporated in the wind pressure equation.

Velocity wind pressure (imperial): qz = 0.00256 Kz Kzt Kd Ke V2

We must reference this equation to calculate the inlet velocity relative to elevation for the RWIND Simulation CFD wind tunnel. To consider only velocity rather than pressure from this equation, the basic wind speed is multiplied by the square-root of each coefficient. Notice the velocity variable in Eq. 26.10-1 is squared which requires the square root of the coefficients to be considered.

$Inlet\;velocity\;=\;V\sqrt{K_e\;\cdot\;K_{d\;}\cdot\;K_z\;\cdot\;K_{zt}}$

Because the ASCE 7-16 standard does not address wind CFD analysis and magnitude of the required inlet velocity, it is difficult to draw comparisons. Therefore, this is the closest estimate for calculating the RWIND Simulation inlet wind velocity per the code.

• ### Will other standards be added to the wind profile generation options in RWIND Simulation?

Additional standards and codes to generate the wind profile automatically in RWIND Simulation will be added in the future. We are always considering feedback from our current customers on which standards will be beneficial.

• ### How to enter a covering of a bucket foundation up to 10 cm below the top edge of the bucket in RF-/FOUNDATION Pro?

This is possible in RF-/FOUNDATION Pro by defining the soil profile.

In the input dialog box '1.1 General Data', you can find the button that opens the dialog box for defining the soil profile.

In the 'Soil Profile' dialog box, you can then set the PGL altitude and PGL'.

Important:
The profile of the grade line must not be higher than the profile of the ground elevation.
For a bucket foundation, PGL or PGL' refers to the upper edge of the bucket.

• ### Does the software RWIND Simulation consider the wind directionality factor (Kd) from the ASCE 7-16?

The wind directionality factor (Kd) from the ASCE 7-16 Sect. 26.6 is considered in the ASCE 7-16 wind load profile or RWIND Simulation calculation and can be adjusted manually by the engineer. The wind directionality factor (Kd) can be considered in RWIND Simulation by modifying the factor under the wind veloicty profile settings before running RWIND Simulation in RFEM.

This factor for various structure types can be determined from table 26.6-1 from the ASCE 7-16 [1].

• ### How to import a parameterized cross-section table into the cross-section library?

004290

The cross-section library in RFEM or RSTAB offers the option to import a list of parameterized cross-sections into the user-defined cross-section library with the 'Import Cross-Section Table from File' function.

Figure 01 - Importing Cross-Section Table from File

For this task, the cross-section shape to be imported must be compatible with a shape that can already be parameterized in the Dlubal cross-section library (also known as a cross-section table). This cross-section shape then determines the type and order of the import parameters.

To import a user-defined cross-section table, proceed as follows:

1. In the Dlubal Cross-Section Library, find a cross-section table that is compatible with the cross-section table that you want to import.

Here, the parameterizable cross-section types (thin-walled, solid and timber construction) specify the necessary parameters in the correct order for the import directly from the input boxes in the input boxes from top to bottom.

Figure 02 - Parameters and Sequence of Regular Parametrically Defined Cross-Sections

For rolled cross-section types, you can find the required parameters in the correct order using the 'Parametric Input' function.

Figure 03 - Parameters and Sequence of Rolled Parametrically Defined Cross-Sections

2. Create a CSV table for the cross-section table to be imported, which describes in each line a unique cross-section via the parameters 'Name' + Shape Parameters based on the previously defined parameter list and order.

The shape parameters must be specified in mm

Figure 04 - Creation of CSV File

For reasons of data representation, the individual cross-section names in the CSV file should start with the same Text Fragment as the CSV file name itself. This ensures that the new cross-section table in RFEM or RSTAB bears the name of the CSV file.

3. Import the CSV file with the cross-section table used into the user-defined cross-section library.

Figure 05 - Importing Cross-Section Table

4. Use the cross-sections of the newly imported cross-section table in your models.

Figure 06 - Use of New User-Defined Cross-Section Table

• ### I would like a stair railing, for which I have created a set of rods, measured. The profile is a hollow profile. Can the proof of stability of the whole system be made for this purpose, or do I have to transfer this to all stock in STAHL EC3 in a replacement bill?

For a vault-free cross-section, a proof of the complete system is recommended using theory II. Order - internal forces and local imperfections. The entry of the effective lengths and nodal bearings (with staff sets) can thus be omitted. However, please activate gamma_M1 for cross-section verification.
• ### Can I define my own soil layers for a soil profile with soil constants?

Yes, you can. You can create your own soil profile that meets your requirements.

By default, there is a soil layer with the thickness of 10 m and a 'Gravel, Well-Graded (GW) applied to the soil profile.

In the dialog box for creating the soil profile, you can define an individual soil profile for your construction project and also define new additional soil layers here. See Figure 01.

There are various materials available in the material library. See Figure 02.

You can specify thicknesses of the individual layers. The interactive graphic on the right side of the dialog box helps you to check the entry. It is possible to adjust the soil parameters individually for the respective layer (see Figure 03) and to reject the values in the library. As soon as you adjust the soil parameter, the name of the soil layer is marked with *.
• ### How do I activate the earth covering (permanent)? The corresponding check box is deactivated.

As soon as RF‑FOUNDATION Pro has determined the ground failure resistance according to EN 1997‑1 Annex D and/or performed the sliding resistance design, it is necessary to enter the soil profile.

In this case, the soil profile entry also controls the location of the earth covering.
See Figure 01.

The weight density applied to the earth covering can also be defined in the dialog box for the soil profile.

If you manually set the allowable ground pressure and deactivate the sliding resistance design, it will not be necessary to enter the soil profile. In this case, you can specify the earth covering directly in the dialog box 1.4. See Figure 02.

• ### Question about RSTAB and RFEM:

To permanently save the settings under Units and Decimal Places, you have to save the cross-section (see Figure 1). Then, you can use the "Import Profiles" button to export all cross-sections (see Figure 2). In this way, it is also possible to quickly switch between the metric and imperial system, among other things.

• ### Why do I have to define a soil profile in FOUNDATION Pro? I have already specified the allowable soil pressure.

The soil profile in RF‑/FOUNDATION Pro is not only required for the determination of the allowable soil pressure.

It is necessary to also enter the soil profile when performing one of the following designs:
- Ground failure design by determining the resistance according to EN 1997‑1 Annex D
- Sliding resistance design
- Settlement calculation

If the ground failure resistance is specified by the user and the settlement calculation and the sliding resistance design are deactivated, the evaluation of the soil profile is not required by the program and the dialog box for entering the soil profile is disabled.

1 - 10 of 12

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.

#### Your support is by far the best

“Thank you for the valuable information.

I would like to pay a compliment to your support team. I am always impressed how quickly and professionally the questions are answered. I have used a lot of software with a support contract in the field of structural analysis, but your support is by far the best. ”