In: Civil Engineering
What are some clues in design nomenclature that refers to design strength ? I am having trouble wrapping my head around when to introduce the resistance factor to the nominal strength of a member. From what I understand the "available strength" = "design strength" = Nominal Strength x Resistance Factor.
Is it safe to assume that if a problem statement refers design strength the value must include the resistance factor ?
.Yes, the understanding is correct.The nominal strength reduced by the 'resistance factor' is termed as the design strength φ Rn.
Following are the reasons to use Φ (phi) factor:
If a problem says design strength, then it is already reduced by the resistance factor.
Refer Section 9.3 of ACI 318-14. below is the reference image for the same.