Non-Linear Temperature in Beam Elements

Analysis, Guides

In this video, you will learn about the required steps to assign non-linear vertical temperature profiles to beam elements.

The workflow includes two steps:

  • tweaking the user-defined cross-section (solid section)
  • and assigning the temperature values using the programme module SOFiLOAD.

Cross-Section

First, you can create a non-linear vertical temperature profile only for user-defined cross-sections and not for the standard cross-sections in the SOFiSTiK library.

And second, you will have to assign temperature values in cross-section points. Those points can be either stress points or geometry points. Import to remember, that you name them properly, as you will need that information later when defining the temperature values in SOFiLOAD.

Furthermore, in case you have several structural lines with different cross-sections, it is necessary to create the same points in all of the used cross-sections.

Temperature Values

Once the cross-section points are placed in the cross-section, it is time to assign the temperature values. Therefore, use the programme module SOFiLOAD. Once the temperature is assigned to the reference point it will be applied for the entire width of the cross-section.

  • Step One
    Use the BEAM command to assign the temperature values to the cross-section reference points.
  • Step Two
    With the EVAL TYPE TEIG input, you request the equivalent linear temperature load and Eigen stresses

All that’s left, is running the linear analysis to get results

Enjoy watching the video!

Notes:
The non-linear temperature type of loading can’t be combined with the linear- or constant type of temperature loading in module SOFiLOAD with the command COPY. The non-linear temperature loading generates Eigen-stresses in the cross-section (similarly to the creep and shrinkage effects). Therefore, they can only be combined in the programme module AQB using the command COMB.

The temperature gradient change doesn’t follow a polygonal line. It either follows the local y or the local z direction. And only one in one load case.

Software version: SOFiSTiK 2022-04