Question:
Is it possible to define the damage parameter ζ manually for the calculation with RF‑CONCRETE Deflect? In such a way that it should always be at least 0.5?
Answer:
No, it is unfortunately not possible.
If the "Tension Stiffening" option is not applied for the calculation, the damage parameter ζ is either "0" for "uncracked sections" or "1" for "cracked sections." For this, see the technical article about the distribution of the damage parameter ζ under Downloads below.
Nevertheless, the manual specification of ζ = 0.5, for example, is not possible.