An extruded beam has the cross section shown. Determine $($a$)$ the location of the shear center $O,$

$($b$)$ the distribution of the shearing stresses caused by a $50kN$ vertical shearing force applied at

$O.$

Ans: $($a$)e=48\mathrm{.}7mm$

$($b$)=0$ at $A,=15\mathrm{.}95$ and $26\mathrm{.}6$MPa at $B,=73\mathrm{.}1$ and $43\mathrm{.}9$MPa at $D,=60\mathrm{.}5$

MPa at midpoint of DE