Improving interlaminar fracture toughness of flax fiber/epoxy composites with chopped flax yarn interleaving  

作　　者：LI Yan WANG Di MA Hao 

机构地区：[1]School of Aerospace Engineering and Applied Mechanics, Tongji University [2]Key Laboratory of Advanced Civil Engineering Materials, Ministry of Education, Tongji University

出　　处：《Science China(Technological Sciences)》2015年第10期1745-1752,共8页中国科学（技术科学英文版）

基　　金：supported the National Basic Research Program of China("973"Project)(Grant No.2010CB631105)

摘　　要：In this research, unidirectional flax fabrics reinforced epoxy laminates were intedeaved with randomly oriented chopped flax yarns at various yarn lengths and contents. Mode I interlaminar fracture toughness of the laminates was evaluated via Double Cantilever Beam （DCB） tests. The results showed that Mode I interlaminar fracture toughness increased with the introduction of the chopped yarns. With moderate yarn length and content, the best toughening effect （31% improvement in Mode I inter- laminar fracture toughness） was achieved. It was observed with the aid of Scanning Electronic Microscopy （SEM） that the in- troduction of the chopped yarns resulted in more tortuous in-plane crack propagation paths as well as the ＂trans-layer＂ phe- nomenon and fiber bridging effect of both the unidirectional yams and the chopped yams. These hindered the growth of the crack and led to more energy dissipation during delamination progress. Excessive yam length or content would induce unstable crack propagation and thus weakened the toughening improvement. No remarkable change was found in the tensile properties and the Charpy impact strength for the interleaved laminates, which indicated that this interleaving method was effective on interlaminar toughening without sacrificing the comprehensive mechanical properties of the laminates.

关 键 词：natural fiber reinforced composites interlaminar fracture toughness interlaminar toughening INTERLEAVING fiberbridging trans-layer effect 

分 类 号：TQ327[化学工程—合成树脂塑料工业] TB33[一般工业技术—材料科学与工程]