Example 7.3: Plot the variation of following effective stiffness terms against the fibre volume fractions for both Voigt and Reuss approximation. .

Solution: The plots of   are shown in Figure 7.10 and plots of are shown in Figure 7.11. The Voigt approximation gives upper bound for the terms   whereas Reuss approximation gives the lower bound for these terms. However, for the terms   Voigt approximation gives lower bound and Reuss approximation gives upper bound.