Effective length - wood beam

[nuche1973]

Ok, this is a very specific one for those of you who have worked in wood alot: I am calculating the maximum bearing capacity of a double wood top plate (SPF #2). I am using the 2005 NDS, Chapter 3.3 Bending Members-Flexure. For the Beam Stability Factor CL the slenderness ratio is required (RB). In order to calculate this I need to determine the effective length of my beam. The values given are based on a simple span beam, whereas, the double top plate is in three span conditions. I am assuming 4ft sticks for the beams and uniform loading. Since the effective length is based on Euler theory, how does one account for multi-span conditions in determining the effective length? Or, is it acceptable to use the given tabulated values, since the top plate will be fastened to the studs and I can assume pin-pin end conditions? Any suggestions or insight will be greatly appreciated.

 

[JAE]

Isn't your double top plate bending about its weak axis? Per NDS 3.3.3 CL = 1.0

 

[nuche1973]

JAE,
Ummm, yes it is. Ok, duh, I missed that part. There are days when I wake up and feel like the dumbest man on the planet and there are days when I confirm it. Thanks.