A notched $(150\backslash$times $150$ mm$2)$ aluminium plate $($Figure $2)$ is used to reinforce the main spar cap and subjected to $=$

$45.$ and $=57.$ bending moments. The thickness of the plate is $(8$ mm$),$ and the diameter of the circular

hole is $(10$ mm$).$

It is intended to replace the aluminium plate with a composite laminate.

However, due to new design constrains, the total thickness of the composite

plate should not be higher than $(3$ mm$).$ The material properties of the

selected carbon$/$epoxy laminate are given in Table $3.$ Assume that $0$o and $90$o

plies do not contribute towards the shear strength of the laminate. Calculate the minimum number of control plies $(0\backslash$deg $,\backslash$pm $45\backslash$deg and $90\backslash$deg $)$ that can meet the specified design constrains.

$$ Following the good practise rules for the design of aerospace composite structures, suggest an acceptable laminate

stacking sequence.

$$ Determine the Margin of Safety $($M$.$S$.)$ of the proposed laminate for $$ and $$ and discuss the safety issues of the

composite plate based on the calculated M$.$S$.$ values.