The scaling issue in the penetration of concrete targets by rigid projectiles - Revisited

The penetration of limestone targets by rigid projectiles: Revisited

“…In fact, the ratios of R t /f c * for the three pairs range between 12.2 and 12.9, suggesting that, indeed, there may be a relation between the scaling issue, as manifested by the different R t values, and the size effect in the expected compressive strength (f c *) of the three limestone cylinders with the different dimensions. This correlation can account for the scaling issue in the limestone's penetration data observed by Frew et al (1999), as was also found by Rosenberg et al (2020) for concrete targets penetrated by rigid projectiles of different size. We should note that these R t /f c * ratios are much higher than the corresponding ratios (R t /Y) for metallic targets with strength of Y, which are in the range of 4-6, as shown by Rosenberg and Dekel (2009).…”

“…These simulations showed that the scaling issue is related to the D/d ratio, as in the empirical model of Rosenberg and Kositski (2016), but they did not account for the full extent of the scaling effect. Thus, one has to look for other reasons for the scaling issue, as we do next by following the approach in Rosenberg et al (2020) for concrete penetration.…”

Response and closure to: A comment on “Constant deceleration approach for the penetration analysis of rigid projectiles into concrete targets: Revisited” by D.Z. Yankelevsky and V.R. Feldgun, Int. J. Prot. Struct., pp. 1–18 (2020)

“…Their modified expression appears again in the most recent paper by Rosenberg, Vayig, and Malka-Markovitz (RVM, 2020) that has just been published (and was not available to us when our paper was already processed). In this new paper, the authors equate the quadratic term to P-D P (instead of P-D above), but the term D P is the projectile diameter (as above); hence, no change is made in that respect.…”

A comment on “Constant deceleration approach for the penetration analysis of rigid projectiles into concrete targets: Revisited” by D.Z. Yankelevsky and V.R. Feldgun, Int. J. Prot. Struct., pp. 1–18 (2020)

“…We do not wish to repeat our main findings here and to contrast them with the other types of modeling. The interested reader is referred to the detailed analyses in Rosenberg and Dekel (2010), Rosenberg and Kositski (2016), and Rosenberg et al (2020). Instead, we wish to point out several inaccurate statements concerning our work, made by Yankelevsky and Feldgun (2020), or YF (2020) for short.…”

“…Equation (2) accounts (empirically) for the scaling issue in the penetration of concrete targets by rigid projectiles. This issue was further analyzed in Rosenberg et al (2020) were a physically based model for the scaling issue is offered. Note that this important subject is totally absent from the models which YF (2020) advocate so warmly.…”