I really appreciate both of your responses. I understand now. Essentially your fb is reduced because S would be larger when accounting for 3 2X10s in the following equation:
fb = M/S
Thus, fb is the stress that the beam or all three 2x10s are experiencing at the same time. I’m rambling but...
It’s been a while since I last worked on wood design. I’m working on a girder/beam design. The girder will be three (3) 2X10 placed right next to each other. When calculating Fb’, since I have three 2X10s do I calculate Fb’ for one 2X10 and then multiply by 3 to account for all three 2X10?
I...
