Energy dissipation in pearlitic steel under impact loading

Energy dissipation plays a crucial role in the mechanical performance of pearlitic steel, particularly as structural materials subjected to impact loading. However, quantitatively distinguishing various dissipative mechanisms remains a great challenge due to the extremely short temporal and small spatial scales of shock deformation. In this paper, we address this challenge by performing molecular dynamics simulations of pearlitic steel under planar shock waves, generated by a piston moving at constant velocities. It is revealed that, the ratio of energy dissipation to input energy is inversely correlated with the piston velocity. The shock energy dissipates via the heat and structural contributions. The former accounts for 100 % of the dissipation for pure elastic deformation, while it still consumes >93 % of the dissipation when the deformation occurs beyond elasticity. In structural dissipation, the main contributor is the formation of new surfaces due to voids and spallation.