关键词: 横向效应, 螺旋切缝, 冲击破碎, 数值模拟

Abstract: To further enhance the post-target damage effectiveness of the penetrator with enhanced lateral effect (PELE), a new PELE design featuring spiral slits is proposed. Based on experimental validation of the numerical simulation model, the finite element method, combined with fracture softening and random failure algorithms, was used to study the penetration, fragmentation, and post-effectiveness of different PELE structures. The impact of rotational speed and direction on the fragmentation and damage effectiveness of the spiral slit PELE was also analyzed. Experiments were conducted to compare the post-target fragmentation dispersion and damage effectiveness of conventional PELE and spiral slit PELE. The results indicate that the penetration of a 12 mm thick 4340 steel target by PELE occurs in two stages: hole formation and hole expansion. During penetration, the fragmentation of the conventional PELE shell is relatively random, while the cracks in the slit PELE propagate along the Slits direction. The initial crack propagation of the axially grooved PELE starts near the projectile/target contact interface. The cracks in the spiral slit PELE initiate at the projectile/target contact interface and extend toward the tail along the slit, with the fragments undergoing tensile fracture due to circumferential tensile stress. The fragmentation degree of the spiral slit PELE is the highest among the three types, and its fragment size and dispersion are the most uniform. Its fragmentation dispersion range increased by 38% and 42%, respectively, compared to the conventional and axially slit PELE. The post-target fragments of conventional and axially slit PELEs exhibit a conical distribution, while the fragments of the spiral slit PELE are approximately planar in distribution. When the projectile's rotation direction is opposite to the slit direction, the fragmentation is more uniform, the fragment dispersion is more even, and the perforation diameter in the post-target is generally larger.

Key words: lateral effect, screw slit, impact crushing, numerical simulation