冲击环境下层状冰细观破碎机理及渐进破坏模型研究

In recent years, with frequent occurrence of extreme weather all around the globe, the hail impact has become a realistic threat for aerospace industries increasingly. In this project, the layered ice is proposed to study the dynamic mechanical behavior of hail which naturally forms in layers. The dynamic mechanical properties and the mesoscopic crushing characteristics of layered ice will be reserched by the representative impact experiments. And the mesoscopic crushing mechanism of impacted layered ice will be further studied. On the basis of above results, the failure modeling of layered ice will be established. Specific contents of the project includes: 1) Establishing the strength criterion of layered ice with strain rate and temperature effects by dynamic mechanical testing under different conditions of strain rate and temperature. 2) Studying the mesoscopic failure characteristics of layered ice due to the cracks evolution by ice impact test to reveal the mesoscopic crushing mechanism of ice. Then the evolution equation of cracks will be built up by using the mesoscale damage mechanics. 3) According to the evolution characteristics of cracks and based on the theory of statistical damage mechanics, the progressive failure modeling of ice will be established in the project. The research achievements of the project are helpful to better understand the damage and failure behavior of ice under impact loading, and can also provide reference for safe design of aerocraft-structure.

近年来，随着全球性极端恶劣天气的频发，冰雹撞击日益成为威胁航空航天飞行器飞行安全的新课题。本项目冰雹逐层形成的特性，以层状冰为对象，实验研究其动态力学性能及细观破碎特性，分析其细观破碎机理，进而从细观层次出发建立其破坏力学模型。具体内容包括：1）利用带低温试验条件的准静态材料试验机及Hopkinson压杆装置研究不同温度层状冰在不同应变率下的力学行为特性，分析应变率、温度等对其动态压缩强度的影响规律。在此基础上，构建计及应变率、温度耦合效应的冰强度准则；2）利用冰弹撞击实验装置，结合高速摄影观测及分析，研究层状冰弹丸内裂纹演化等细观破碎特性，探讨层状冰的细观破碎机理，并结合细观损伤力学，构建裂纹演化方程；3）利用统计损伤力学及裂纹的演化规律，进一步构建冰的宏观渐进破碎本构模型。项目研究成果有助于深化对冰材料在撞击下的破坏行为的认识，同时为飞行器结构防护冰雹撞击安全设计研究等提供参考。

近年来，随着全球性极端恶劣天气的频发，冰雹撞击日益成为威胁航空航天飞行器飞行安全的新课题。本项目针对冰雹形成的特性，以层状冰和含杂质冰为对象，实验研究其动态力学性能及破碎特性，分析其破碎机理，进而建立本构模型研究其对目标的毁伤特性。主要结果包括：1）利用带低温试验条件的准静态材料试验机及Hopkinson压杆装置研究了单一性状冰、层状冰和含杂质冰在不同应变率下的力学行为特性，分析了层间结构和杂质对其动态压缩强度的影响规律；2）利用冰球撞击实验装置，结合高速摄影观测及分析，研究了不同类型冰球的撞击力特性，探讨了不同类型冰球的破碎机理；3）构建了冰的本构模型，利用数值模拟研究了其对典型靶板的毁伤特性。项目研究成果有助于深化对冰材料在撞击下的破坏行为的认识，同时为飞行器结构防护冰雹撞击安全设计研究等提供参考。