Write a computer code that transforms stress and strain $($under plane stress assumption$)$ between coordinate sys$-$

tems $x-y$ and $x_1-x_2,$ with $x_1$ oriented at an angle $(+$ defined as CCW$)$ from $x.$ Use your code to calculate the

following:

For AS$4/3501-6$ carbon$/$epoxy you can use the following material properties: $E_1=20$msi,$E_2=1\mathrm{.}45$msi,

$G_{12}=1\mathrm{.}0$msi, and

$u{?}_{(}()()12)=0\mathrm{.}3$

$($a$)$ For the lamina shown above, compute the stress components oriented with respect to the material principal axes

for global stress state ${}_x=80$ksi,${}_y=-50$ksi,${}_{xy}=15$ksi. Hint$($s$)$: ${}_{}=70\mathrm{.}9429$ksi.

$($b$)$ For a lamina oriented at $23,$ what global stress state $($in $x-y$ based coordinates$)$ must you apply to achieve the

local stress state ${}_1=2280$MPa;${}_2=0,$ and ${}_{12}=0$ corresponding to pure tensile fiber failure for AS$4/3501-6$

carbon$/$epoxy$.$ Hint$($s$)$: ${}_{11}=1932{10}^3$kPa.