Abstract: The two-dimensional molecular dynamics calculation is used to simulate ejection and damage phenomena. The intermolecular force is described by Morse potential. Molecules are initially located in equilibrium position and spaced so that the free surface has an angle shape for simulating real machined surface. Shock wave may be produced by motion of first layer of molecules (piston) or by impact of flyer of molecules. When the disturbance arrives at free surface, the boundary molecules start to run away from it with large velocity and the inside damage begins. The ratio of ejection velocity to the surface one changes from 1 to 3 and it is dependent on the shock strenth, surface angle and material property. When the semiangle is bigger than 60°, the boundary molecules can not run away from others, i.e. the ejection disappears. It also disappears when shock strength is lower than a limit value dependent ont he surface angle and material. In the both ejection and jetless cases the calculation shows the process of microvoid formation and growth.

Key words: molecular dynamics, simulation, ejection, microvoid