Oblique impact damage by spherical particles onto Si 3N 4

Abstract

Impact angle changes affect the resulting stress field in the target such that the initiated crack morphologies are changed from a Hertzian cone crack to surface ring cracks as the impact angle decreases. This is because an impact at a large impact angle creates fully developed Hertzian cone cracks that degrade the strength of the target material drastically. However, an impact at a small angle produces less severe damage because the resulting surface ring cracks cause only a modest strength degradation. Numerical stress analysis using a computer supports the explanation of the generated stress level under an oblique impact.