Abstract To reveal the effect and necessity of introducing the Lode angle into a fracture criterion in ballistic performance simulations of metallic Plates, experimental and numerical work were carried out on 6061-T651 aluminum alloy (AA6061-T651) thick Plates. Firstly, a series of ballistic tests were conducted via a one-stage gas gun test facility that blunt-nosed projectiles of φ12.68 mm penetrated onto 20 mm thick AA6061-T651 Plates at impact velocities ranging from 280.0 m/s to 400.0 m/s. Subsequently, experimental results in terms of initial versus residual velocities of the projectiles and the failure characteristics of the Plates were reported. Experimental results showed that shear plugging was the dominating failure mode of the perforated Plates. Meanwhile, numerical results corresponding to the ballistic tests were obtained using finite element (FE) simulations via the commercial software ABAQUS/Explicit. Specially, we compared the results between simulations using a Lode dependent fracture criterion and a Lode independent. Finally, the FE simulations indicated that using a Lode dependent fracture criterion better predicts the ballistic behavior of the thick AA6061-T651 Plates under impact of blunt-nosed projectiles. It is also found that the Lode angle affects the fracture behaviour of the AA6061-T651 significantly. And this effect decreases with the increase of the materials’ ductility.

中文翻译：

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6061-T651铝合金厚板对钝头弹弹道冲击行为的试验与数值研究

摘要 为了揭示在金属板弹道性能模拟中将洛德角引入断裂准则的效果和必要性，对6061-T651铝合金（AA6061-T651）厚板进行了实验和数值研究。首先，通过单级气枪测试设备进行了一系列弹道测试，φ12.68 毫米的钝头弹丸以 280.0 米/秒至 400.0 米/秒的冲击速度穿透 20 毫米厚的 AA6061-T651 板s。随后，报告了弹丸初始速度与剩余速度的实验结果以及板的失效特性。实验结果表明，剪切堵塞是穿孔板的主要破坏模式。同时，对应于弹道测试的数值结果是通过商业软件 ABAQUS/Explicit 使用有限元 (FE) 模拟获得的。特别地，我们比较了使用依赖于矿脉的断裂准则和独立于矿脉的模拟之间的结果。最后，有限元模拟表明，使用 Lode 相关断裂准则可以更好地预测 AA6061-T651 厚板在钝头弹丸冲击下的弹道行为。还发现 Lode 角度显着影响 AA6061-T651 的断裂行为。而这种影响随着材料延展性的增加而减弱。有限元模拟表明，使用 Lode 相关断裂准则可以更好地预测 AA6061-T651 厚板在钝头弹丸冲击下的弹道行为。还发现 Lode 角度显着影响 AA6061-T651 的断裂行为。而这种影响随着材料延展性的增加而减弱。有限元模拟表明，使用 Lode 相关断裂准则可以更好地预测 AA6061-T651 厚板在钝头弹丸冲击下的弹道行为。还发现 Lode 角度显着影响 AA6061-T651 的断裂行为。而这种影响随着材料延展性的增加而减弱。