金属泡沫材料冲击动力学行为及其机理研究

Metal foam is a class of materials with dual features of function and structure, and can provide outstanding performance in the impact energy absorption. However, the study on the dynamic behavior of the foam under impact is not enough due to the complexity of the micro-structure and not applicable for the traditional SHPB facility. In these years, good understanding its dynamic behavior and control mechanisms have remained a hot topic. This project, through theoretical, numerical and experimental approaches, aims at studying the dynamic behavior and the characteristics of metal foam under impact loading, revealing the strain rate sensitivity and its mechanisms，and exploring the relationships between the micro-structural parameters of the cells and the macro level dynamic properties of the metal foams. The project will also develop a impact shear-compression experimental technique and investigate the dynamic properties and the failure behavior of the metal foam under complex impact loading. Meanwhile, a methodology combing experimental results and numerical simulation in studying the mutiaxial dynamic behavior of metal foam is proposed. The numerical study in this project will be implemented based on a three-dimensional Voronoi random model, combinging with the finite element analysis. The dynamic experimental investigation will be mainly conducted using Hopkinson bar systems, based on an accurate description of the mechanical behavior of visco-elastic rods and the accurate correction for the attenuation and dispersion of stress waves in a visco-elastic rod. The study of this project is very important and academically significant for deep understanding the dynamic behavior of metal foams under various impact loadings, and will provide the guidance for the design of metal foams to enhance the impact resistance capacity and the crashworthiness of the structure.

金属泡沫是一类兼具功能和结构双重属性的工程材料，在结构抗冲击、吸能方面有着突出表现。由于材料微结构的复杂性及传统动态实验技术的局限性，目前对金属泡沫冲击动力学行为的认识还不够清楚，研究金属泡沫材料冲击动力学行为及其机理已是当前亟待解决的热门课题。本项目拟通过理论、数值分析和实验手段，重点研究金属泡沫材料的冲击动力学行为，揭示其应变率敏感性及其机理，创建胞元微结构特征参数和泡沫材料宏观动力学性能间的关系，发展金属泡沫材料压剪复合冲击实验技术，研究复杂冲击下材料的动态力学性能和失效行为，建立实验和数值模拟相结合的泡沫材料双轴动力学行为的研究方法。研究中的数值分析将基于三维Voronoi 随机模型，结合有限元分析完成；实验研究将基于霍普金森测试系统和对粘弹性杆中应力波的衰减和弥散的精确修正。此项目研究对掌握金属泡沫材料冲击动力学行为及机理、指导结构抗冲击及耐撞性设计具有重要的理论意义和应用价值。

金属泡沫是一类兼具功能和结构双重属性的工程材料，在结构抗冲击、吸能方面有着突出表现。由于材料微结构的复杂性及传统动态实验技术的局限性，目前对金属泡沫冲击动力学行为的认识还不够清楚，研究金属泡沫材料冲击动力学行为及其机理已是当前亟待解决的热门课题。本项目通过理论、数值分析和实验手段，对泡沫金属在准静态和动态单轴/多轴加载下的力学行为开展了深入细致的研究。重点研究了金属泡沫材料的数值建模技术及其冲击动力学行为、创建了胞元微结构特征参数和泡沫材料宏观动力学性能间的关系、发展了金属泡沫材料压剪复合冲击实验技术，研究了复杂冲击下材料的动态力学性能和失效行为，建立实验和数值模拟相结合的泡沫材料多轴动力学行为的研究方法。项目组2015年-2018年有本项目资助的论文共发表31篇，其中SCI二区收录文章12篇，SCI三、四区收录文章11篇，会议论文8篇，国家发明专利1项。项目研究成果可为金属泡沫材料的抗冲击、吸能优化设计提供理论和研究方法，也为金属泡沫材料的工程应用提供技术支持。