255x
004176
2023-04-25

FAQ 005378 | Does RFEM check the applicability limits of AISI Table B4.1-1?

Question:
Does RFEM check the applicability limits of AISI Table B4.1-1?

Answer:
The safety factor, Ω or resistance factor, Φ used in chapter E through H are only appropriate for sections that comply with the limitations in Table B4.1-1. For all other sections that exceed any of the limits, higher safety factors, Ω or lower resistance factors, Φ are applied according to section A1.2(C). In RFEM, this limitation is checked by default. The user has the option to deactivate this check in the Strength Configuration.

image@

For general/complex sections such as the sigma section used in Example III-14 of AISI D100-17 (shown in Image 03), the more conservative factors are automatically applied. As a result, Φ-c equals 0.80 is used in RFEM design checks. However, the manual calculation shows that the sigma section actually meets the applicability limits and Φ-c equals 0.85 can be used instead.

  1. image@