Comparison among depths of penetration of different targets subjected to rigid projectile impact

The present paper discusses the ratios of DOP (depth of penetration) of different targets under the same penetration condition according to the dimensionless formula of DOP of different targets penetrated by a non-deformable projectile. It is declared that various targets may be equivalent to each other. Finally we discuss the applicable range of the equivalence and the feasibility of targets substitution by integrating the available test data.