When a concrete slab is set upon the top flange, its effect is like a lateral support (composite construction), preventing problems of torsional buckling stability. If there is a negative distribution of the bending moment, the bottom flange is subjected to compression and the top flange is under tension. If the lateral support given by the stiffness of the web is insufficient, the angle between the bottom flange and the web intersection line is variable in this case so that there is a possibility of distortional buckling for the bottom flange.
RFEM and RSTAB programs provide parameterized input as an advantageous product feature to create or adjust models by means of variables. This article will show you how to define global parameters and use them in formulas to determine numerical values.
Structures in RFEM 6 can be saved as blocks and reused in other RFEM files. The advantage of dynamic blocks with respect to non-dynamic blocks is that they allow interactive modifications of the structural parameters as a result of modified input variables. One example is the possibility to add structural elements by changing only the number of bays as an input variable. This article will demonstrate the aforementioned possibility for dynamic blocks that are created by scripting.
The new RFEM software generation provides the option to perform stability design of tapered timber members in line with the equivalent member method. According to this method, the design can be performed if the guidelines of DIN 1052, Section E8.4.2 for variable cross-sections are met. In various technical literature, this method is also adopted for Eurocode 5. This article demonstrates how to use the equivalent member method for a tapered roof girder.
In RFEM, loads can be freely defined on surfaces. It is impossible, however, to define a variable loading on, for example, circular surfaces. However, you can still create this type of loading by using a free circular load.
In RFEM, if you want to insert a tapered member with intermediate nodes into an existing model, the issue often arises how to determine the individual cross-section depths of the tapered members quickly. The "Connect Lines or Members" command comes in handy for this purpose.
In RF-/STEEL EC3, you can optimize a cross-section automatically within the design. To do this, select the corresponding cross-section in Table 1.3 or define variable parameters for a welded cross-section.
You can use the "Free Circular Load" option in RFEM to apply a partial uplift force to a cone‑shaped floor slab. It can be defined as linearly variable. The definition of center C and the outer boundary R can be specified easily, using the select function.
In RFEM 5 and RSTAB 8, it is useful to parameterize frequently occurring components with variable dimensions. In the Block Manager, you then can specify new dimensions and import them in a new or existing file.