@article{TENG2023, 
author = {Xuebei TENG and Yingjie XU and Weihong ZHANG and Xinyu HUI and Weiwei LIU and Chengyan MA},
title = {Improving Mode Ⅱ delamination resistance of curved CFRP laminates by a Pre-Hole Z-pinning (PHZ) process},
year = {2023},
journal = {Chinese Journal of Aeronautics},
volume = {36},
number = {2},
pages = {316-324},
keywords = {CFRP, Curved laminates, Delamination resistance, Fracture toughness, Mode Ⅱ, Z-pins},
url = {https://www.sciopen.com/article/10.1016/j.cja.2022.09.018},
doi = {10.1016/j.cja.2022.09.018},
abstract = {This paper presents an experimental investigation of the Mode Ⅱ delamination 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 Mode Ⅱ fracture 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.}
}