In RFEM, you can modify stiffnesses for materials, cross-sections, members, load cases, and load combinations in many places. There are two options in RF‑DYNAM Pro for considering these modifications when determining the natural frequencies.
The determined values for the influence ordinates are displayed as decimal numbers with up to six decimal places by default. This is usually sufficient for the influence lines of internal forces.
According to DIN EN 1990/NA:2010‑12 – NDP to A.1.2.1(1) Comment 2, it is necessary to apply only one of the two climatic actions in the combination expressions for actions according to 6.4.3 and 6.5.3 in the case of places located up to +1,000 m above mean sea level if snow and wind are available as collateral actions, in addition to non‑climatic leading action.
The insulating glass pane design places a special requirement on the load application point of the loading. For example, wind loads and loads due to fall protection may appear. For this, the wind load should be applied on the external glass side and the handrail load should act on the internal glass pane.
The form-finding process in RF-FORM-FINDING displaces the corner nodes of FE elements of a membrane surface in space until the defined surface stress is in equilibrium with the boundary conditions. This displacement is independent of the element geometry. In the case of elements with four corner nodes, the free displacement may cause spatial drilling in the element plane and thus exceed the validity limits of the calculation; therefore, triangular elements are generally recommended for form‑finding systems. Triangular elements remain independent of the corner node displacement and stay within the calculation limitations.
When changing the units from the metric to the imperial measurement system, it is not necessary to change all the units individually. To do this, corresponding unit profiles are available in the "Units and Decimal Places" dialog box, which you can activate as shown in the picture.
In RFEM and RSTAB, there are two predefined unit profiles available by default. These profiles cover the metric and the imperial systems of measurement. You can individually adjust the units predefined by Dlubal Software, including the decimal places used. To avoid losing the changes you have made, you can save a new profile for the units (see Item [1] in the picture). The stored profile can be loaded again (see Item [2] in the picture) or transferred from PC to PC. To do this, simply copy the content of the "Units" folder in the RFEM or RSTAB file directory from one PC to another (see Item [3] in the picture). In this way, you can achieve an office standard regarding the units used in all your workplaces.
Just as in the RFEM Display Navigator, you can set the distribution of internal forces in surfaces in RF‑STEEL Surfaces. Since deformations are always the result of the FEM calculation, the corresponding forces will be recalculated. This means that the internal forces on an FEM element are calculated depending on the composition (triangular or square) in three or four places. In order to obtain continuous internal forces and thus a smoothed distribution, these internal forces have to be interpolated. Interpolation is done by selecting the "Distribution of internal forces" option in the surfaces.
During the cooperation between the structural and design engineers, the DXF format is often used if there is no direct interface. However, the geometrical data of these DXF files are not always accurate. For example, an inaccuracy in the third decimal place is not noticeable, but it can lead to numerical problems when generating the FE mesh in RFEM.