Before revision: If it is assumed that the composite material behaves as a linear-elastic material, i.e., abiding Hooke's law for some elastic modulus of the composite and some strain of the composite , then equations and can be combined to give Finally, since , the overall elastic modulus of the composite can be expressed as Lower-bound modulus Now let the composite material be loaded perpendicular to the fibers, assuming that .
After revision: If it is assumed that the composite material behaves as a linear-elastic material, i.e., abiding Hooke's law for some elastic modulus of the composite and some strain of the composite , then equations and can be combined to give Finally, since , the overall elastic modulus of the composite can be expressed as Reuss modulus Now let the composite material be loaded perpendicular to the fibers, assuming that .