Question

Find the longitudinal tensile strength of resulting composite.

Given: Ti-aluminum metal matrix composite- Fiber volume fraction: 27%,Ti matrix: at 427°C, Em = 87.5 GPa, νm = 0.3. Alumina fibers: at 427°C, Ef = 379 GPa, νf = 0.27

Ti-aluminum metal matrix composite Fiber volume fraction: 27% Ti matrix: at 427°C, Em 87.5 GPa, v 0.3 . Alumina fibers: at 427"C, E,-379 GPa, v,-0.27 o Find the longiiudinal tnsile sirengih of resuling cormpositc

Answer 1

Ans) We know,

$\sigma$_c = E_c x strain

where, $\sigma$ _c = tensile strength of composite

E_c = modulus of elasticity of composite

Also, E_c = E_fV_f + E_mV_m

where, V_f = volume of fiber

V_m = volume of matrix

=> E_c = (379 x 0.27) + (87.5 x 0.30)

= 129 GPa

At 427^oC , tensile strength of alumina fiber ($\sigma$_f) = 280 MPa

   Strain = Stress/ Modulus of elasticity

= 280 / 379000

= 7.388 x 10^-4

Since strain is same for fiber, matrix and composite ,

Tensile Strength of composite = 129000 x 7.38 x 10^-4

= 95.20 MPa or 95.20 kN/m²