Refined modelling of hypervelocity impact crater size predictions

Hypervelocity impact crater formation represents a phenomenon of great scientific interest, with important applications in aerospace engineering. In this work, prediction models to estimate the size of craters resulting from high velocity and hypervelocity impacts are analysed and optimized, comparing them with the experimental data available in literature. In particular, discrepancies between predictions and observed results are highlighted and their causes are investigated; possible explanations, based on physical phenomena affecting crater formation and mathematical factors employed in the formulations, are proposed. Subsequently, a process of optimizing the prediction models is conducted, with the goal of reducing the error in crater size estimates with a custom optimized formulation. Results are presented through graphs and in terms of average deviation of the analysed models and the developed one with respect to experimental data; for normal impacts with spherical projectiles on ductile metal targets the proposed model achieves a mean relative percentage error of about 8.7%, significantly lower than the values obtained using the ESABASE Thick Plate and Christiansen models.