1680x
004968
2021-04-08

Question

How do I enter the temperature difference for a T‑beam defined as a rib?


Answer:

The "temperature difference" load type always refers to the cross-section height in RFEM and RSTAB. For a rib, however, the plate component is not taken into account when determining the cross-section height, which is necessary to determine the load size. As concerns the rib, it is therefore necessary to define the loads for the member and the surface separately.

Example

Assumptions:

  • Cross-section rib → rectangle 200/200
  • Surface thickness → 200 mm
  • Temperature difference between the top and the bottom of the component = 200 K.
Result of Deformation when Modeling Component as T‑Beam (Cross‑Section)

The load for the model using surfaces and the rib may be composed as follows:

The temperature load of the surface is also determined according to this scheme.

In the attached model file, there are two further modeling variants, in which the temperature distribution for the plate component was designed in a more realistic way. The deformations in these two model variants are slightly larger for this example than in the other models.