The torsion box shown below is symmetric with respect to the

The torsion box shown below is symmetric with respect to the horizontal and is subjected to a constant torque T = 38000 N.m. acting clockwise. Calculate the shear flow q in walls 1, 2, 3, 4 and 5. The thickness of each wall is as follows: t_1 = 1 mm, t_2 = 1.5 mm, t_3 = 3 mm, t_4 = 2 mm and t_5 = 4 mm. Wall 1 is semicircular. What is the maximum shear stress and in which wall does it occur?

Solution

Maximum shear strain and stress are not at the farthest distance from the rotational axis of a homogeneous non-circular member.

In a shaft of circular cross section, the maximum shear stress occurs at all points located at the greatest distance from the center

maximum shear stress occurs where there ismaximum value of Q/t

the stress is inversely proportional to the thickness