低面内性能损伤的Z-pin增韧技术研究

Study on Z-pin enhancement technology with low in-plane damage

通过弯曲、拉伸试验研究了Z-pin预制孔植入工艺在降低复合材料层合板面内性能损伤方面的表现。对固化后的Z-pin增强试件进行损伤检测发现Z-pin预制孔植入工艺可显著降低Z-pin植入后造成的纤维卷曲、绕流稀释及断裂等初始损伤。试验结果显示直径为0.28 mm的Z-pin采用预制孔植入工艺植入试件后,试件拉伸、弯曲强度分别只降低了3.02%和3.33%,这表明Z-pin预制孔植入工艺可显著降低对试件面内性能的损伤;直径为0.18 mm的Z-pin采用预制孔植入工艺植入试件后,试件拉伸、弯曲强度分别只降低了1.69%和1.12%,这说明细小直径Z-pin在实现试件层间增韧的同时能进一步降低其对试件面内性能的损伤。此外,通过对试件失效机制的分析得出:合理设置Z-pin的排布方式、尽量使用细小直径Z-pin、试件铺层设计中尽量减少0°铺层的使用等都有利于减轻对试件面内性能的损伤。

This article presents an experimental investigation on the efficiency of the Z-pin pre-hole insertion process in reducing the in-plane damage while improving the delamination resistance of carbon fibre/epoxy laminates.The results show that the Z-pin pre-hole insertion process could reduce the fiber crimp,flow dilution and fracture.Specifically,the tensile strength and flexural strength of the laminates reinforced with Z-pin(0.28 mm in-diameter)were only reduced by 3.02%and 3.33%,respectively.It shows that Z-pin pre-hole insertion process could significantly reduce the in-plane damage of Z-pinned laminates.Furthermore,the tensile strength and flexural strength of the laminates reinforced with Z-pin(0.18 mm in-diameter)were only decreased by 1.69% and 1.12%,respectively.It shows that fine Z-pin could further reduce the in-plane damage of Z-pinned laminates while achieving interlaminar toughening.In addition,through the analysis of the failure mechanism of Z-pinned laminates,it is concluded that the in-plane damage of the laminates could be reduced by reasonably setting the arrangement of Z-pin,using fine Z-pin and reducing the use of 0°ply in design of layer.