复合材料多层级界面细-微-纳观实验与模拟  

Meso-micro-nanoscale experiments and simulations on the hierarchical interfaces of composites

作　　者：李倩[1] 李岩[1,2] LI Qian;LI Yan(School of Aerospace Engineering and Applied Mechanics,Tongji University,Shanghai 200092,China;Key Laboratory of Advanced Civil Engineering Materials,Ministry of Education,Tongji University,Shanghai 200092,China)

机构地区：[1]同济大学航空航天与力学学院,上海200092 [2]同济大学先进土木工程材料教育部重点实验室,上海200092

出　　处：《中国科学：物理学、力学、天文学》2023年第1期25-36,共12页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：国家重点研发计划(编号:2020YFD1100402-4);国家自然科学基金(编号:11625210);中央高校基本科研业务费专项资金资助项目。

摘　　要：植物纤维具有绿色环保、来源丰富等优点,拥有与人造纤维相媲美的比力学性能,有望成为重要的增强纤维种类.植物纤维独特的多层级结构会影响其增强复合材料的载荷传递模式.为了实现植物纤维增强复合材料的界面设计,量化其多层级界面性能十分必要.本文首先应用纳米压入技术,依次采用单步和多步准静态纳米压入方法确定了植物纤维增强复合材料多层界面力学性能,包括模量和硬度以及能量耗散、裂纹萌生和扩展能力.然后采用动态纳米力学分析技术,评估了循环加载下植物纤维增强复合材料多界面的疲劳特性.最终结合细观尺度有限元模拟,引入纳观尺度获得的多界面性能参数,重现了复合材料多层级界面带来的多阶段破坏行为.结果表明,植物纤维多层级结构与其增强复合材料多阶段失效行为相关,植物纤维增强复合材料多层级界面依次呈现由裂纹萌生和扩展引起的失效.纳观尺度实验结果为深入剖析细微观尺度复合材料界面性能和失效机制提供了支持和依据.Plant fibers possess the advantages of green environmental protection and abundant sources.They exhibit specific mechanical properties comparable to man-made fibers and can become an important reinforcement of composites.Their unique hierarchical structures affect the load transfer mode of plant fiber reinforced composites(PFRCs).To serve the task of interfacial design of PFRCs,it is necessary to quantify their hierarchical interfacial properties.First,by applying the nanoindentation technology,the mechanical properties of the multi-layer interface of PFRCs,including the modulus,hardness,energy dissipation,and ability of crack initiation and propagation,were measured using the single-step and multi-step static nanoindentation methods.Subsequently,the fatigue characteristics of multiple interfaces in PFRCs under cyclic loading were evaluated via the nanoscale dynamic mechanical analysis.Finally,combined with the finite element simulation at the mesoscale,the multi-stage failure behavior of the hierarchical interfaces in the composites was presented by introducing multiple interface performance parameters obtained at the nanoscale.The results showed that the hierarchical structure of plant fibers was associated with the multi-stage failure behavior of PFRCs.The hierarchical interfacial failure caused by the crack initiation and propagation at the three types of interfaces occurred sequentially.The experimental results at the nanoscale provide support and basis for an in-depth analysis of the interfacial properties and failure mechanisms of composites on meso-microscale.

关 键 词：复合材料 纳米压入 多层级界面 

分 类 号：TB332[一般工业技术—材料科学与工程]