On the oblique impact of a rigid sphere against a rigid-plastic solid

Previous workers have sought to explain the variation in crater volume observed when hardened steel spheres impact at different angles against mild steel plates by numerically modelling a rigid sphere striking an ideal rigid-plastic half-space. The present note shows that the discrepancy between experiment and their throretical prediction from this model can be significantly reduced by incorporating a more accurate calculation of the area of contact into the analysis.