CALCULATION OF MECHANICAL-PROPERTIES OF SOLIDS USING MOLECULAR-DYNAMICS METHOD

We describe the calculation of mechanical properties of solids using t he molecular dynamics method. The thermal expansion coefficient and el astic constants of alpha-Fe are calculated using an empirical potentia l, that is, the Johnson potential. The thermal expansion coefficient i s calculated using a differential operation of the temperature depende nce of the lattice constant obtained from the NPT ensemble molecular d ynamics analysis. Reasonable agreement is found between the analytical results and measured data up to the phase transition temperature. The elastic constants are calculated from the stress-strain curves obtain ed from the NVT ensemble, the initial lattice constant of which is mod ified based on the result of the NPT ensemble. The analytical results agree reasonably well with the measured data up to 400 K.