层合复合材料z-pinning增强技术的力学进展

 z-pinning技术是自20世纪90年代中期发展起来的一种增强层合复合材料层间韧性的新技术。此项技术通过在层合板内嵌入体分比小于5%的z-pin,能使层合板的I型层间断裂韧性提高十几倍,减少50%由低能量冲击所产生的层间分层,并且只造成层合板面内拉压强度的少量退化或不退化。同时,z-pinning技术较之其他层间增强技术,如编织、纺织和缝合技术等,又具有易于加工,且便于控制工艺质量等优点。因此,这一技术在近年来逐渐受到重视,并在一些航空、航天复合材料结构中得到了应用。简要介绍了z-pinning技术的工艺特点,重点综述这一领域细观力学模型与实验测试等力学分析工作的最新进展,并对准确评估z-pin力学行为的研究工作进行了展望。

Advances on Modeling Through-the-thickness Reinforcement of Laminated Composite by z-pinning

Through-the-thickness reinforcement of laminated composites by z-pinning has attracted more and more attention since the middles of 1990s.The insertion of z-pin,with the volume fraction of fibrous z-pin less than 5%,can lead to an up to 18-fold increase in mode I fracture resistance of the z-pinned polymer com- posite laminates,with a retention of 91%-98% the tensile and 100% of the compressive strengths.There is al- so a 50% reduction in the delamination area after the low-energy impact.Compared to the other reinforce tech- nologies,such as weaving,knitting,braiding,and stitching,etc.,z-pinning is easier to be manufactured and controlled in its quality,which has been applied to some engineering structures in aerospace industry in recent years.In this paper,the z-pinning technology is briefly described and recent advances on modelling the me- chanical behaviour of z-pin is reviewed.