# Bending a Beam to Produce Uniform Tension

by mrh5529
Tags: beam, bending, produce, tension, uniform
 P: 5,462 I think we need to hear from the mike exactly what he means, I agree that a constant tension implies a constant curvature. Since the tension is one half of the bending moment couple it implies a constant moment since $\frac{1}{\rho } = \frac{M}{{EI}}$ as we are told the beam has a constant? rectangular cross section. A constant moment can only be achieved by applying a couple, not a force which subjects the beam to a variable moment depending upon the distance from the force. This was my method (2) in post #2. It has occured to me that by " constant across a section" mike may mean uniform across an exploratory free body section, similar to the stress block we assume for compression in the concrete that we assume in some theories of reincforced concrete. Alternatively for an isotropic beam that has developed a full plastic moment both the compression and tension stress blocks will be rectangular at the exploratory section.