Improving ModeⅡdelamination resistance of curved CFRP laminates by a Pre-Hole Z-pinning(PHZ)process  

作　　者：Xuebei TENG Yingjie XU Weihong ZHANG Xinyu HUI Weiwei LIU Chengyan MA 

机构地区：[1]State IJR Center of Aerospace Design and Additive Manufacturing,Northwestern Polytechnical University,Xi'an 710072,China [2]Shaanxi Engineering Laboratory of Aerospace Structure Design and Application,Northwestern Polytechnical University,Xi'an 710072,China [3]Shandong Institute of Non-Metallic Materials,Jinan 250031,China

出　　处：《Chinese Journal of Aeronautics》2023年第2期316-324,共9页中国航空学报（英文版）

基　　金：supported by the National Key Research and Development Program of China(No.2021YFF0500100);the National Natural Science Foundation of China(No.11872310)。

摘　　要：This paper presents an experimental investigation of the ModeⅡdelamination resistance of curved CFRP laminates reinforced with Z-pins.A Pre-Hole Z-pinning(PHZ)process is developed to reduce the in-plane damage of the Z-pinned laminates.The microstructural observation of the Z-pinned laminate specimens indicates that the PHZ process can effectively decrease the defects including the Z-pin offset angle and the area of eyelet zone.The influences of the volume fraction and diameter of Z-pin on the fracture toughness and the delamination crack growth rate of the specimens under End Notch Flexure(ENF)loading are then determined experimentally.The test results show that Z-pin increases the interlayer stiffness of the laminate.The delamination crack growth rate is reduced with the increase of Z-pin diameter and volume fraction,and a reduction up to 40%is achieved compared with the specimens without pins.Furthermore,the ModeⅡfracture toughness is significantly improved with the increase of Z-pin volume fraction.When Z-pin volume fraction increases by 1%,the achieved fracture toughness is about 200%higher compared to the unpinned laminates.

关 键 词：CFRP Curved laminates Delamination resistance Fracture toughness ModeⅡ Z-PINS 

分 类 号：V214.8[航空宇航科学与技术—航空宇航推进理论与工程]