3. 1 Comparison of stress-strain curves
Figure 3 (a) and (b) respectively shows the stress- strain curves for simulation models that have the crys-
tal volume fractions f 10 and 34%. We used nominal
strain and true stress for stress-strain curves. It is clear that
the size efects are very small under the calculated condi-
tions. For the models with lower crystal volume fractions
(Fig. 3 (a)), a slight stress overshoot is visible around the
yield point, yy 0.05, and the stress becomes almost con-
stant for yy > 0.1. For the models with higher volume fractions (Fig. 3 (b)), oscillation is apparent for yy > 0.2.
This is because the crystal particle is deformed, as shown
in the following sections. Figure 3 (c) displays the stress-
strain curves for models with R 12.6 nm. Young's mod-
ulus of the composite increases as the volume fraction in-
creases because the crystal phase has a higher Young's
modulus than the amorphous phase. The efective Young's
modulus(22), which is obtained from the angle average of
the elastic tensor, of the crystal is about 198 GPa, and Young's modulus of the amorphous block is about 64 GPa. The yield stress also notably increases with the increase