Mechanical behavior of Al/Ep cast braided metal-wire skeleton tubular structures applied to projectile shells

Al/Ep composites cast with braided metal-wire skeleton tubular structures exhibit promising potential for hard-target penetration applications due to their synergistic combination of structural reinforcement and energetic-material characteristics. This study systematically investigated the dynamic compressive responses of steel-wire and tungsten-wire skeleton tubes with Al/Ep mass ratios of 3:7, 4:6, and 5:5 using split Hopkinson pressure bar (SHPB) tests over an overall strain-rate range of 300–1200 s -1 , together with the penetration damage behavior of a tungsten-wire skeleton tubular projectile against a thick concrete target. The experimental results revealed strain-rate sensitivity across all specimen groups. For the 3:7 specimens, the maximum failure strength and failure strain increased by 165.4% and 147.7%, respectively, in the steel-wire skeleton tubes as the strain rate increased from 300 to 1200 s -1 , and by 179.1% and 176.3%, respectively, in the tungsten-wire skeleton tubes over the range of 500–1200 s -1 . The specimens with Al/Ep mass ratios of 4:6 and 5:5 showed the same strain-rate-sensitive trend, although the magnitude of the increase depended on the mass ratio and skeleton material. At a strain rate of 1200 s -1 , both the maximum failure strength and failure strain decreased with increasing Al/Ep mass ratio, while the tungsten-wire skeleton tubes consistently exhibited higher values than the corresponding steel-wire skeleton tubes. A phenomenological polynomial constitutive model was established to interpolate the dynamic compressive responses within the strain-rate tested range. In the penetration test conducted at an impact velocity of 240.67 m/s, the projectile penetrated the concrete target to a depth of 120 mm and produced a damaged region measuring approximately 300 mm × 200 mm. The simulated penetration depth was 125.3 mm, corresponding to a relative error of 4.42%, supporting the applicability of the numerical model for interpreting the present penetration process.