Abstract Micro-spalling is a dynamic fragmentation process that is coupled with shock-induced overheating and melting. It has been observed in series of shock experiments and in several modern industrial applications such as inertial confinement fusion and laser-shock surface micromachining. Modeling micro-spalling is beyond the scope of traditional damage mechanics which ignores solid–liquid transformation. Here, for the first time, we develop a continuum model of micro-spalling by coupling hydro-elastic–plastic-damage mechanics and high-pressure melting kinetics. A two-scale framework is proposed for modeling mechanical responses of partially melted materials in shock-induced micro-spalling. Temperature and pressure dependence of shock-induced melting rate is formulated. In modeling dynamic ductile damage, temperature and (partial) melting effects are involved. The model is implemented into a finite element code and used as a predictive tool to simulate plate impact spalling experiments on aluminum. The simulations reveal typical characteristics of micro-spalling resulted from coupling effects of dynamic damage and melting, concerning evolutions of damage and phase distributions and thermodynamic paths. The simulations are in good agreement with previous experiments and molecular dynamics simulations. Particularly, the calculated free surface velocity profiles and spall strengths are quantitatively consistent with experimental measurements in a wide range of initial temperature up to the melting point. These results indicate that the present model is a reasonable uniform description of spalling process, covering transition from classical solid spalling to melting-accomplished micro-spalling.

中文翻译：

---

冲击引起的微剥落中动态延性损伤和熔化的耦合：建模和应用

摘要 微剥落是一种动态破碎过程，伴随着冲击引起的过热和熔化。它已在一系列冲击实验和几个现代工业应用中观察到，例如惯性约束聚变和激光冲击表面微加工。对微观剥落进行建模超出了忽略固液转换的传统损伤力学的范围。在这里，我们首次通过耦合水弹塑性损伤力学和高压熔化动力学开发了微剥落的连续模型。提出了一种两尺度框架，用于模拟冲击引起的微剥落中部分熔化材料的机械响应。制定了冲击诱导熔化速率的温度和压力依赖性。在模拟动态延性损伤时，涉及温度和（部分）熔化效应。该模型被实施为有限元代码，并用作模拟铝板撞击剥落实验的预测工具。模拟揭示了由动态损伤和熔化的耦合效应引起的微观剥落的典型特征，涉及损伤和相分布的演变以及热力学路径。这些模拟与之前的实验和分子动力学模拟非常吻合。特别是，计算出的自由表面速度分布和剥落强度与实验测量在很宽的初始温度范围内直到熔点在数量上是一致的。这些结果表明，本模型是对剥落过程的合理统一描述，