Beer & Johnston — Shearing Stresses in Beams: Problem 6.76

6.75 and 6.76 A thin-walled beam has the cross section shown. Determine the location of the shear center $O$ of the cross section. (From Fig. P6.76: Left vertical flange height $h_1 = 80\text{ mm}$, middle vertical flange height $h_2 = 60\text{ mm}$, right vertical flange height $h_3 = 40\text{ mm}$. The spacing between the first and second flanges is $50\text{ mm}$, and the spacing between the second and third flanges is $50\text{ mm}$. All segments have a uniform thickness $t = 6\text{ mm}$.)