When performing seismic analysis according to EC8, using a design spectrum and defining a behavioral factor (q) for the ductility of the structre, i see here (https://knowledge.autodesk.com/support/robot-structural-analysis-products/learn-explore/caas/CloudHe...) that Robot sets the displacement ductility factor (μ) always equal to q, allegedly "as stated in sec. 3.2.2.5 of EC8". This is however not mentioned in sec. 3.2.2.5.
μ=q is true for T > T_C, but for smaller oscillation periods the relationship is:
μ = 1 + (q-1) * TC/T
This is rather badly mentioned in point (3) of section 5.2.3.4 in EC8 (which is related to specific rules for concrete), but also mentioned in informative annex B.
Ahmed Elghazoulis book "Seismic design of buildings according to EC8" also mentions the μ to q relation in section 3.4.1. (picture below)
Shouldn't this be corrected in the software? Is there a setting i can change somewhere to accomodate for it?
