Frequently Asked Questions (FAQ)

Search FAQ




Customer Support 24/7

Knowledge Base

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.

Newsletter

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

  • Answer

    For irregular member structures, the load generators "From Area Load on Members via Plane" or with "Cells" can be helpful. However, both functions assume that the nodes of the members lie in one plane. In the settings of the load generators, you can increase tolerances for the nodes to also detect nodes that lie outside the plane (see Figure 01). In interaction with the "fictitious lines", it is possible to load even more complex structures.
  • Answer

    To only consider the stiffness modification (see Figure 01) for certain load combinations, it is necessary to deactivate this option for the corresponding load combinations in the calculation parameters (see Figure 02).
  • Answer

    You can check the load application with the Project Navigator - Results → Load Distribution. In sections, it is possible to display the load distribution graphically by the perimeter and height in a graphic representation.

    Figure 1 displays a free variable load on a cylinder along its circumference. Figure 2 displays a free variable load by height. The load distribution can clearly be seen by the load distribution in the horizontal and vertical section.

  • Answer

    In Figure NA.1A, there is a snow load zone map of Germany displayed by DIN EN 1991-1-3/NA. The exact assignment of snow load zones of the administrative units, in particular in the area of the zone boundaries, must be requested from the competent authorities. The German Institute for Building Technology DIBt publishes a table 'Allocation of Snow Load Zones According to Administrative Boundaries' for each federal state on the website https://www.dibt.de/en/service/notices/
     
    For locations of snow load zones 1 and 2 in the North German Plain, it is also necessary to check if they are within the meaning of DIN EN 1991-1-3/NA, Section 4.3, Defined Regions. For these locations, the table 'Allocation of Snow Load Zones According to Administrative Boundaries' shows the footnote 'North German Plain'. 

    According to DIN EN 1991-1-3 and DIN EN 1991-1-3/NA, higher values than specified in DIN EN 1991-1-3 and DIN EN 1991-1-3/NA may result for certain layers of the snow load zone 3. These locations are displayed in the table 'Assignment of Snow Load Zones According to Administrative Boundaries'.

    In addition, it is necessary to consider the results of the research project of the German Meteorological Service called 'Surface analysis of snow load data in five counties and their comparison with the snow load zone data of DIN 1055-5: 2005 as a pilot study for the revision of the snow load zone map'.

    These special conditions are also available in the Dlubal Online Service. The snow load zones with special regulations are indicated by an asterisk. The special control is also displayed as a comment in the snow load zone. Figure 1 shows the snow load zone 3* for the city of Altenau. For Altenau, an increased snow load has to be taken into account. This is also displayed as a comment.
  • Answer

    A free variable load allows you to apply a load on surfaces whereby it can vary in height and perimeter.

    Figure 1 shows a round container that is only loaded by more than half of the perimeter in the direction of the surface normal. To define a load variable over its perimeter, select the option 'Variable' in 'Along Perimeter'. Use the corresponding button to enter the factors for the load including the angles at which they occur. Furthermore, the rotation axis has to be defined. The factor kα creates a reference to the load value p of the initial dialog box.

    Alternatively, it is possible to split the surface into corresponding surface components. Subsequently, a surface load can be applied to the relevant surface components.

    The container in Figure 1 has been modeled with two partial surfaces in Figure 2. Thus, it is possible to apply a surface load to the container half to be loaded.

  • Answer

    Such input is not possible as a surface load because there is no load type to have the force act locally on a projected surface. In such a case, you have to work with line loads. These can later be loaded according to the line rotation. The detailed procedure shows the video. As you can see in the video, lines have to be integrated manually into quadrangle surfaces. Apart from that, the line rotation should be checked.
  • Answer

    Unfortunately, such a possibility does not exist in the program. There is only the option to edit the existing load and redefine it, if necessary.
  • Answer

    When I have a trapezoidal load value that tends to zero for example, it may happen that the scale is correct for small values displayed. In this case, there is a setting error in the display properties.
    It will simply proceed as follows:
    • Right click on the load to access its context menu
    • Select "Display Properties ..."
    • Click on the magnifying glass at the height scale of size 1 [kN / m]
    • Fill in eg the most minimal value of the minimum limits at 0.1%
    • Confirm by clicking on OK
    The scale of your drawing will be immediately adjusted and correct.

    Important note :
    1- The value zero is not displayed on the loads (cf. figure 3)
    2- When a zero value is displayed, it certainly contains decimal digits. By zooming in, you discover that the diagram does not form a closed angle at the end. (Cf. figure 4)
  • Answer

    First, it should be checked in which direction the self-weight of the structural elements acts. You can also display the self-weight graphically by using the 'Display Navigator' (see Figure 01). It often happens that the user does not convert the data when switching the global Z-axis, in the calculation parameters, and then only adjusts the geometry. The self-weight acts in the wrong direction and must be signed correctly in the load case (see Figure 02).
  • Answer

    In contrast to the normal surface or nodal load, a free load is defined by an influence range and influenced elements. By definition, the free loading is applied only to the areas of the selected elements lying within this influence range.


    A free load is defined via absolute coordinates, independent of the elements of the model. For entering data, you can define them comfortably by selecting model nodes, but they will not be linked to the selected nodes. If the model is then e.g. moved, the free load remains in its assigned position.

    If an imperfection generated by RF-IMP is used as a pre-deformed FE mesh, the free loads are applied to this deformed structure. This may then exist beyond the influence range and receives no load.



    If the load is expected to be linked to the structure and also be moved for displacements and generated imperfections, standard loads must be used. Alternatively, it is also possible to increase the influence range of the free load as required to still stress the entire structure.


    A simple check of the applied loading is possible by displaying the load distribution in the Project Navigator - Results dialog box.

1 - 10 of 105

Contact us

Contact Dlubal Software

Did you find your question?
If not, contact us via our free e-mail, chat, or forum support, or send us your question via the online form.

(267) 702-2815

info-us@dlubal.com

First Steps

First steps

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

Your support is by far the best

“Thank you very much for the useful information.

I would like to pay a compliment to your support team. I am always impressed how quickly and professionally the questions are answered. In the industry of structural analysis, I use several software including service contract, but your support is by far the best.”