The effective strength of metallic plates perforated by rigid projectiles

A note on the cavitation phenomenon in metallic plates perforated by sharp-nosed rigid projectiles

“…Moreover, they demonstrated that the dynamic flow stresses, as determined at these strains and strain-rates, account for perforation data of various metallic plates, such as the elasto-plastic RHA steel, the moderately-hardening Al 6061-T6 and the strain-hardening 304 stainless steel. The above relations have been shown to predict the experimental results in Rosenberg et al (2018a), where various metallic plates were impacted by the hard steel cores of the 7.62 mm APM2 projectiles. It seems that one can use the Recht-Ipson model, together with the relations described above, in order to predict the value of V bl for any projectile/plate pair.…”

“…For thinner plates, with 1/3 ⩽ H/D 0 ⩽ 1.0, they found that σ r = 2Y. Rosenberg et al (2018a) showed that the correct dynamic flow stress of the target material (Y) has to be determined by a Kolsky-bar test at a high rate (about 10 4 s −1 ), and at a strain of about 0.3. These are the average values for the rate and the strain in a metallic plate perforated by sharp-nosed rigid projectile, as was shown by the numerical simulations of Rosenberg et al (2018a).…”

“…Rosenberg et al (2018a) showed that the correct dynamic flow stress of the target material (Y) has to be determined by a Kolsky-bar test at a high rate (about 10 4 s −1 ), and at a strain of about 0.3. These are the average values for the rate and the strain in a metallic plate perforated by sharp-nosed rigid projectile, as was shown by the numerical simulations of Rosenberg et al (2018a). Moreover, they demonstrated that the dynamic flow stresses, as determined at these strains and strain-rates, account for perforation data of various metallic plates, such as the elasto-plastic RHA steel, the moderately-hardening Al 6061-T6 and the strain-hardening 304 stainless steel.…”

“…At this point we should quote some of our experimental results regarding D/D 0 values for various metallic plates. First, we examined the hole diameters in the aluminum and copper plates which were impacted by the steel cores of the 7.62 mm APM2 projectiles in Rosenberg et al (2018a). These holes had a diameter of 6.0 mm which is slightly lower than the diameter of the hard steel core (6.1 mm), due to the elastic recovery of these plates.…”

The penetration and ricochet of ogive-nosed rigid projectiles obliquely impacting metallic targets

“…Most of these were performed with aluminum targets having von-Mises strength of 0.43 GPa, since this is the dynamic flow stress of the 6061-T6 alloy, at a plastic strain of about 0.3 and at a strain rate of 10 4 s −1 . As was shown by Rosenberg et al (2018), these are the average values of the strain and the strain-rate in a metallic plate during a perforation process. Using these values for the average dynamic flow stresses simplifies the analysis without impeding its relevance.…”