Bending

For a beam subjected to bending,

• Elongation occurs on one surface and shortening on the opposite surface of the beam. There is a (neutral) plane through the beam which does not change in length during bending.
• Plane cross sections of the beam remain plane and perpendicular to the neutral axis of the beam.
• Any deformation of a cross section of the beam within its own plane is neglected.
• The normal stress on a cross-section of the beam is distributed linearly with the maximum normal stresses occuring on surfaces farthest from the neutral plane.