It is desired to produce an aligned and continuous fiber-reinforced epoxy composite having a maximum of 40 vol% fibers. In addition, a minimum longitudinal modulus of elasticity of 55 GPa (8 × 106 psi) is required, as is a minimum tensile strength of 1200 MPa (175,000 psi). Of E-glass, carbon (PAN standard modulus), and aramid fiber materials, which are possible candidates and why? The epoxy has a modulus of elasticity of 3.1 GPa (4.5 × 105 psi) and a tensile strength of 69 MPa (11,000 psi). In addition, assume the following stress levels on the epoxy matrix at fiber failure: E-glass, 70 MPa (10,000 psi); carbon (PAN standard modulus), 30 MPa (4350 psi); and aramid, 50 MPa (7250 psi). Other fiber data are given in Tables B.2 and B.4 in Appendix B. For aramid fibers, use the minimum of the range of strength values provided in Table B.4?