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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AnswerThere are many ways to define a member for a surface. One of them is to move the surface a small part of the original plane and to add a coupling. The workflow is illustrated in the video.
AnswerThe cause may consist in the definition of member eccentricities. For a better overview, the origin lines are automatically hidden for eccentric members. In some cases, it may appear that a member end is not sufficiently supported (see Figure 01, left). However, the meshed line acts in the background. This can clearly be displayed by hiding the members in the Display navigator (see Figure 01, right).In Figure 01, the line at the common node has not been geometrically separated. For this reason, there is no graphical connection line representing the eccentricity, which would result in this case. However, because of the setting displayed in Figure 02, the node is still meshed with the vertical member.To visualize the graphical connection line, it is recommended to divide the member or line at this node (see Figure 03).
In the case of a ground failure analysis or soil contact stress analysis, the 'equivalent surface' is determined in RF‑/FOUNDATION Pro in order to calculate the soil contact stress.If the foundation dimension is smaller than twice the load eccentricity 'e', the 'equivalent surface' or the 'effective foundation' cannot be determined. In this case, you receive the corresponding error message.In most cases, the problem is that a user has entered too small dimensions of the foundation plate.To remedy the problem, you can manually set greater dimensions. Or select the 'Dimensioning' feature.
AnswerThe axes, to which the support rotations and support eccentricities refer, are preset to the local member axes, which can be displayed with the button under the partial view. However, they can also be switched to the global axis system.
The setting of the load application specified in the Details refers to the principal axes of the respective cross-section. For a Z-section as an example, a box with nine edge nodes is set around the cross-section. The load application is then always related to the rotated principal axis angle and the corresponding eccentricities.
In a 2D model XY with the degrees of freedom (uz/fx/fy), no eccentricity can be defined. The eccentricity usually results in an axial force that is not covered by these degrees of freedom.
You should also be careful when using ribs. In contrast to the 3D model, the effective width also changes the stiffness of the structure.
Therefore, it is generally better to calculate the downstand beam structures in a 3D model.
AnswerWe want to give the user as much freedom as possible for controlling the designs in RF‑/FOUNDATION Pro. The relevant designs according to EN 1992‑1‑1 and EN 1997‑1 are activated by default when creating a new case.These can be partially deactivated. On the one hand, if the design is not required due to the structural specifics of the foundation. On the other hand, due to the testing or verification purposes.However, it should be noted that it is necessary to activate at least one Geotechnical design according to EN 1997‑1.
AnswerFor member hinges where the reference system is related to the local member axes, the release is set directly on the member start or member end. If the hinge is to act directly on the node, the reference system must be related to the global axis system.
AnswerPlease check the entry of loads in the '1.4 Loading' dialog box in the 'Characteristic Values' tab.A possible source of the error is that you have selected individual load cases for the design (that is, for example, self-weight, wind, and so on). Or these load cases are additionally set as 'Permanent'. See Figure 01.Now, the program applies both load cases for the design of the first core width.This is not correct. The design of the first core width only requires the application of the load from one permanent action.For the design of the second core width, the load from a 'permanent and variable combination' is used. It means that you need either a load combination (CO) or a result combination (RC) for this. The entry of a load case (only wind here) is also wrong, since the favourably acting vertical component of the loading is missing. Therefore, you get too large foundations or have to enter a high loading as a 'permanent load' to meet the design.So if you should create a CO for this situation, in which the 'permanent and variable actions' are together and apply these for the design in FOUNDATION Pro, pay attention to the assignment of this CO to a 'permanent + variable action'. See Figure 02.
There are basically two options:
- The use of member eccentricities, see the article Considering eccentricities of members and surfaces
- In the case of, for example, differently defined member hinges in combination with different dimensions of offsets, the use of couplings or rigid members may help, see Figure 1 - Solid model and Figure 2 - Wireframe model
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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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