Rockbadchild said:
mmm, action reaction... the only time the forces from the top vs the bottom would be different in a
cross-sectional slice of a beam is the result of a failure of the beam.
yes the load varies along the beam, but the forces would be equal in each cross-section.
no you miss understood me .. I know you know this it's just a communication issue and with LDI it's a technicality issue... as far as calculation goes I know he is right but practically I would be curious to see it... and I think we have the same opinion in that regard ...
I am saying that the compressive and tensile forces are always the same in each
cross-section slice of the beam... action = reaction ... but yes these forces do change as you go along the beam but in each cross-section if you have a +5 compressive force on top as a result you will have a -5 tensile force as a result at the bottom.