Question

Consider a unidirectional continuous fiber-reinforced composite with epoxy as the matrix with 55% by volume fiber.i. Calculate the longitudinal and transverse moduli when E-glass fiber is used.ii. Calculate the longitudinal and transverse moduli if carbon fibers are used instead of E-glass. Constants:Epoxy modulus = 2.41GPaE-glass fiber modulus = 72.5 GPaCarbon fiber modulus = 230 GPa

Answer 1

Answer:

I)E= 40.95 GPa

II)E=5.29 GPa

Explanation:

I)

Given that

E₁ = 2.41 GPa  ,V₁=1-0.55 = 0.45

E₂ = 72.5 GPa   ,V₂=0.55

Longitudinal moduli  given as ;

E= E₁V₁+E₂V₂

E= 2.41 x 0.45 + 72.5 x 0.55 GPa

E= 40.95 GPa

II)

E₁ = 2.41 GPa  ,V₁=1-0.55 = 0.45

E₂ =230 GPa   ,V₂=0.55

Transverse moduli given as:

$\dfrac{1}{E}=\dfrac{V_1}{E_1}+\dfrac{V_2}{E_2}$

$\dfrac{1}{E}=\dfrac{0.45}{2.41}+\dfrac{0.55}{230}$

E=5.29 GPa