Dynamic contact analysis of rigid sphere impact on amorphous alloys

Classical elastoplastic contact models can accurately predict the coefficient of restitution (COR) and force-displacement relationship of a rigid sphere impacting on a bulk target at lower impact velocities. However, they are invalid at higher impact velocities due to diverse energy dissipation mechanisms and the change of contact area geometry caused by plastic deformation. To solve this problem, we developed a modified elastoplastic contact model by introducing a damping force into the force-displacement relationship. The amorphous alloys were selected as targets due to their propensity for deformation localization, which facilitates additional energy dissipation through shear bands. Using this model, we reproduced the convex force-displacement curves at the loading stage, which is different from the linear relationship in the classical ones. The COR predicted by the present model agrees with experimental data. Furthermore, finite element simulations validate the model’s enhanced predictive capability for both contact force and displacement evolution during the loading stage. As the impact velocity increases, the dimensionless energy dissipation caused by damping raises as well. However, the uniform plastic deformation is always the main energy dissipation mechanism according to the present model. This paper is helpful in understanding the interaction between sphere and target under high-velocity impact.