a$)$ What are Non$-$crimp fabrics $($NCFs$)$ and give their principal advantage

over woven fabrics?

b$)$ Describe the Hand or Wet Lay$-$up manufacturing technique associated

with fibre reinforced composites, its inherent advantages and

disadvantage and a typical product application?

c$)$ In the case of an ideal laminate composite, as depicted below in Figure

$1,$ comprising $3$ laminae of lay$-$up $[0/90/0],$ of an epoxy matrix and

carbon fibres with a fibre volume fraction of $0\mathrm{.}7$ in each lamina,

calculate the effective elastic moduli when

Q$5.$ continued....

Q$5.$ continued....

i$)$ the load is applied in the $0$ direction

i$)$ the load is applied in the $90$ direction

Data: $E_{FL}=140$GPa,$E_M=8$GPa,$E_{FT}=10$GPa

where, $F$ denotes fibre and $M$ denotes matrix, $L$ denotes Longitudinal direction and $T$ the

Transverse direction.

Figure $1$: Laminate schematic

Given the following equations:

$E_1=E_{FL}{V}_f+E_M{V}_M,E_2=\frac{E_{FT}{E}_M}{E_{FT}{V}_M+E_M{V}_F}$