$8\mathrm{.}20.$ A simply supported beam is to carry $0\mathrm{.}2ki\frac{p}{f}t$ dead load and $0\mathrm{.}6ki\frac{p}{f}t$ live load on a span of $24ft.$ A channel section is to be used, and since it is not laterally restrained, torsion is to be considered in the design. Assume the member is torsionally simply supported. After computing the torsional moment, use the generally accepted approximate flexure analogy to make a selection of a channel section from the AISC Manual. Investigate the stress on the selected section using the exact solution based on the stated loading and support condition. Use A$36$ steel.

Problem $8\mathrm{.}20$