## Materials Science and Engineering: An Introduction

$E_{cl} = 60. 27 GPa$
Given: A continuous and aligned fiber–reinforced composite is to be produced consisting of 45 vol% aramid fibers and 55 vol% polycarbonate matrix; the mechanical characteristics of the two materials are given in the Table. The stress on the polycarbonate matrix when the aramid fibers fail is 35 MPa (5075 psi). Required: longitudinal modulus of elasticity for the composite Solution: Using Equation 16.10a: $E_{cl} = E_{m}V_{m} + E_{f}V_{f} = (2.4 GPa)(0.55) + (131 GPa)(0.45) = 60. 27 GPa$