Hi,
I'm a Mech Eng by education, but haven't used many of the skills for a long while. Can someone please run through the equations for calculating bending moment, stress, and deflection of a simply-supported beam? Maybe, for example, using a 2x10 (1.5" x 9.25" wood floor joist???)...

As I said, I knew it once but can't recall it offhand, so a lot of explanation isn't necessary. Some brief instructions and some equations would probably bring it all back (I know trying to explain to someone who's never heard/seen any of it would be very difficult).

Thank you so much.

jimbobcooley

The moment at any point is the resultant of the load times the distance to the support.

Deflection is the (force * length of the beam cubed)/(48*modulus of elasticity*moment of inertia). Modulus of elasticity for yellow pine is about 13 x 10^5. Moment of Inertia for a beam 1.5x9.25 = [(b)(h^3)]/12 = 98.93in^4.

max bending stress = (max moment*half the height of the beam)/moment of inertia