Two simply supported $($both flexure and torsion$)$ beams are subjected to uniform bending,

as shown below. In Fig. A$,$ a narrow rectangular cross$-$section with a width of $t$ and a

depth of $d$ is used, and its flexural strength is designated as $M_x.$ In Fig. B$,$ a narrow

rectangular cross$-$section with a width of $d$ and a depth of $t$ is used, and its flexural

strength is designated as $M_y.$ Under certain condition, $M_y$ can be greater than $Mx.$ The

problem is what the condition is$?$ It is noted that $d$ is much greater than $t.(25\%)$

Use: $E=2000t\frac{f}{c}{m}^2,$ yield stress $F_y=2\mathrm{.}5t\frac{f}{c}{m}^2,G=0\mathrm{.}38E$

Major$-$axis flexural strength $=M_x$

Fig. A

Minor$-$axis flexural strength $=M_y$

Fig. B