1134x
002505
2019-09-23

Question

I designed a steel connection using RF‑JOINTS, then created a model to compare it in RFEM. Why are the results not identical?


Answer:

In RF-JOINTS, an idealized design of a steel connection according to the standard is performed, which cannot be compared easily to an exact FE calculation. The results of the numerical and analytical design methods differ in particular due to the simplifications and assumptions made.

For example, the following points must be considered when calculating a joint as a surface model:

  • Consideration or exclusion of friction/compression/tension within the contact solid (tab "Solid") as well as for the bolts modeled subsequently
  • Consideration of internal forces and deformations within the modeled end plates or something similar, resulting in a redistribution of bolt forces in the FE calculation (in contrast to the idealized design in RF‑JOINTS)
  • Uniform load introduction into the FE model; for example, by using rigid members or rigid surfaces as described in the article "FEM Modeling Approaches of Rigid Connections"

You can find some webinars and technical articles on this topic on our website (see the links below).