Abstract To better understand the oblique penetration behavior of ogive-nosed projectile into aluminum alloy targets, penetration experiments with impact velocities ranging from 700m/s to 1100m/s and oblique angles of 0, 10°, 20° and 40° were conducted. The Length to Diameter (L/D) of the projectiles were 3 and 4, respectively. Failure modes of target and penetration trajectory were obtained from penetration experiments. Based on the local interaction theory (LIT) and resistance to penetration in dynamic expansion theory (DET), a model to depict penetration trajectory was developed by taking the effects of free surface and wake separation/reattachment into account. The effects of free surface and wake separation/reattachment on penetration trajectory were analyzed by combining the experimental data and calculated results. The results showed that the calculation results were in good agreement with the corresponding experimental data. Besides, influences of oblique angle, impact velocity, and L/D of projectile on the penetration trajectory were discussed based on the calculation and experimental result. Ranges of increments of attitude angle of projectiles and oblique angle at the impact velocity of 900m/s were 98% to 274% and 10° to 30°, respectively. Similarly, the increments of attitude angle of projectile varied from 205% to 128% as the impact velocity increased from 800m/s to 1000m/s when the oblique angle was 20°. When it come to the influence of L/D of projectile on the penetration trajectory, the increments of attitude angle of projectiles were 178% and 79.5% for the L/D were 3 and 4, respectively. In summary, the penetration trajectory became more stable with the increase of L/D of projectile and decrease of impact velocity and oblique angle.

中文翻译：

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椭圆形弹头斜穿入铝合金靶材

摘要 为更好地了解卵形弹头对铝合金靶材的斜侵彻行为，进行了冲击速度700m/s～1100m/s、斜角0、10°、20°、40°的侵彻实验。弹丸的长径比 (L/D) 分别为 3 和 4。通过穿透实验获得目标和穿透轨迹的失效模式。基于局部相互作用理论（LIT）和动态膨胀理论（DET）中的穿透阻力，通过考虑自由表面和尾流分离/再附着的影响，建立了描述穿透轨迹的模型。结合实验数据和计算结果，分析了自由表面和尾流分离/再附着对穿透轨迹的影响。结果表明，计算结果与相应的实验数据吻合较好。此外，根据计算和实验结果，讨论了弹丸的斜角、冲击速度和L/D对穿透轨迹的影响。900m/s冲击速度下弹丸姿态角和斜角增量范围分别为98%~274%和10°~30°。同样，当倾斜角为20°时，随着撞击速度从800m/s增加到1000m/s，弹丸姿态角的增量从205%变化到128%。考虑弹丸L/D对穿透弹道的影响，L/D为3和4时弹丸姿态角增量分别为178%和79.5%。总之，