A thin-wall torsion member subjected to torque T has the cross section shown in Figure P6....

A thin-wall torsion member subjected to torque T has the cross section shown in Figure P6.47. The wall thickness t is constant throughout the section. By the theory of Section 6.7, in terms of T, b, and t,

a. derive formulas for the shear stress in the outer walls and the interior web and

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b. derive a formula for the unit angle of twist. Disregard the effects of stress concentrations at interior comers.

FIGURE P6.47