Analysis of stresses and damage due to high-velocity waterdrop impact on coated targets

The evolution of the stresses and the damage in coated targets due to high-velocity waterdrop impacts is investigated. The study combines an analytical-FEM (finite element method) modeling of the impact event in the liquid striker and the solid target and identification of states of stresses that may produce damage in the target. Two such stress states are found, radial tensile stresses that develop in the protective layer and subsurface shear stresses that develop in the protective layer, the substrate and at the interface between them. Comparisons with experimental results demonstrate that the damage patterns which are found at various impact sites result from the intensive radial tensile stresses that are associated with the Rayleigh surface waves. The effectiveness of the protective coating is examined by comparing the evolution of the stresses in coated and uncoated targets.