- #1

davidpotter

- 5

- 0

I'm struggling with something here. I am rusty so have probably just misunderstood something simple mathematically. There are equations to create the Bending moment diagram for each different type of beam subject to a UDL; cantilever, simply supported, fully fixed ends etc.

However I just don't understand how they got them. A simply supported beam with a UDL of q and length L will have bending moments at each end of (qL^2)/2. That I get and can show proof yet its the centre moment I cannot reproduce, (qL^2)/8 Or cantilever at free end, (qL^4)/8EI {I do understand the EI bit btw} and fully fixed beams atall, (qL^2)/12 at ends and (qL^2)/24 in the centre. {Doesn't make sense to me as the reaction forces are still the same as a simply suppoted beam: qL/2} People write these on their beams when doing other structural analysis like its obvious yet I just can't see it. Clearly I've forgotten some basics about beams and I'm baffled, anyone care to help? thanks in advance :)

author: internet việt nam

have a nice day.