Abstract The fundamental assumptions motivating the use of cylindrical (CCE) and spherical (SCE) cavity expansion solutions for the prediction of penetration mechanics are revisited. Predictions of an ovoid of Rankine model (OR), which has been validated relative to axisymmetric numerical simulations, are used as a reference solution for normal penetration into a metallic target. In previous papers it has been observed that the average axial resistance stress is independent of the penetration velocity until a critical value which denotes the onset of separation of the target material from the projectile’s surface. The main conclusion of this paper is that the velocity fields in the CCE and SCE models do not accurately model a realistic flow field for penetration of a projectile. The results in this paper quantify the errors caused by low estimates of the static resistance stress and compensation due to incorrect dependence of the resistance stress on the penetration velocity predicted by the CCE and SCE models.

中文翻译：

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用于渗透的腔扩展模型的基本假设 - 重新审视

摘要 重新审视了推动使用圆柱形 (CCE) 和球形 (SCE) 腔膨胀解决方案预测渗透力学的基本假设。Rankine 模型 (OR) 的卵形预测已通过轴对称数值模拟得到验证，可用作正常穿透金属目标的参考解决方案。在以前的论文中，已经观察到平均轴向阻力应力与穿透速度无关，直到临界值表示目标材料与弹丸表面分离的开始。本文的主要结论是 CCE 和 SCE 模型中的速度场不能准确地模拟真实的射弹穿透流场。