Here are the different EB (Euler-Bernoulli) and TIMO (Timoshenko) deflections for the same simple supported beam with a basic UDL (no self weight, just the external load applied) :
[image: 1761296140644-eng_su92_800.jpg]
[image: 1761296140658-eng_su93_800.jpg]
[image: 1761296140679-eng_su94_800.jpg]
My parameters are:
2Ă10, L=144 in, E=1.7e6 psi, I=98.931 inâ´, A=13.875 in², G=106250 psi, Îş=5/6
As you can see the Timoshenko analysis yields slightly more deflection since we are accounting for deflection from both shear and bending. According to my calculations my results are within less than 0.05% of the theoretical value so I think the algorithm is working correctly
Now I need to check a few different multi-span configurations as well as overhangs to make sure everything is indeed robust.
When I calculate the Timoshenko beam I'm wondering if I should adjust the tabulated E value since it is being adjusted for the shear already by %3 for sawn lumber per Appendix F of the NDS (Sec. F.3). So the listed value is is actually 3% larger than the (shear-free) or true value of E.