Dear Paladin,
I am not a professional and i am student. But i did a heavy research relating this Subject.
First Thing: Which Code you are consulting. In UBC 'R' is over strength factor and not Response modification factor. But in IBC or ASCE or FEMA 'R' is Response modification factor. So you can Relate Fema's 'R' with that mentioned in IBC and ASCE.
Second Thing: I dont know what is your scale to be defined as smaller or bigger. But in my case i used 8.5 from IBC but when carried out a nonlinear analysis it came out to be 4-5. Which as by me a bigger difference. Thus you can end up with 'R' value more or less than Theory's 'R'.
I am not a professional and i am student. But i did a heavy research relating this Subject.
First Thing: Which Code you are consulting. In UBC 'R' is over strength factor and not Response modification factor. But in IBC or ASCE or FEMA 'R' is Response modification factor. So you can Relate Fema's 'R' with that mentioned in IBC and ASCE.
Second Thing: I dont know what is your scale to be defined as smaller or bigger. But in my case i used 8.5 from IBC but when carried out a nonlinear analysis it came out to be 4-5. Which as by me a bigger difference. Thus you can end up with 'R' value more or less than Theory's 'R'.