  Composite of two kinds of grains is modeled in two-dimension and the
elasticity is calculated using molecular dynamics method implementing Gear
predictor-corrector of fifth order. It has been observed that same composite
concentration can be represented by several configurations of the two kinds of
grains. Simulation results show a peak or maximum value of a parameter
proportional to Young's modulus, which quantitatively agrees with reported
experiment results. Ratio of used in simulation has influenced average value of
the mentioned parameter monotonically, it is increasing as the ratio
increasing.
