Problem 4. The longitudinal modulus of a unidirectional glass/epoxy composite containing short aligned fibers, is

E_(1)=39.1GPa

(5.7 Msi). Using Cox's theory, determine the length of the fibers for the properties\

V_(f)=0.60

\

d_(f)=70\\\\mu m(4\\\\times 10^(-4)in)\ E_(f)=70GPa(10.1Msi)\ E_(m)=3.5GPa(0.51Msi)\ v_(m)=0.36

Problem 4. The longitudinal modulus of a unidirectional glass/epoxy composite containing short aligned fibers, is E1=39.1GPa (5.7 Msi). Using Cox's theory, determine the length of the fibers for the properties Vf=0.60 df=70m(4104in)Ef=70GPa(10.1Msi)Em=3.5GPa(0.51Msi)vm=0.36