3D打印连续苎麻纤维增强聚乳酸复合材料的准静态侵彻性能

Quasi Static Penetration Property of 3D Printed Continuous Ramie-fiber Reinforced Polylactic Acid Composites

传统成型工艺制造的合成纤维增强复合材料逐渐无法满足低成本、快速制造、环境友好等要求。因此,选取连续苎麻纤维增强聚乳酸(PLA)基生物质复合材料,采用原位浸渍3D打印工艺成型不同铺层方式的样件。利用准静态侵彻测试评估了铺层方式、支撑跨距与冲头直径比(跨距比)及增强材料对侵彻性能的影响,并通过背光法实时监测侵彻过程中复合材料的损伤行为。结果表明,连续苎麻纤维的加入使样件的侵彻强度提升了51.5%(单向)和52.9%(正交);正交铺层的复合材料样件与单向铺层相比,吸收的能量和最大侵彻力分别提升了24.9%、13.1%;打印样件的侵彻力和能量吸收能力随着跨距比的降低而显著增加,跨距比为10时的正交铺层复合材料与跨距比为5时相比,强度提升了202.4%。最后通过样件的多尺度失效特征分析及侵彻机理研究,揭示了3D打印生物质复合材料的铺层结构-侵彻性能的关系。

The synthetic fiber reinforced composite materials manufactured by conventional manufacturing processes are gradually unable to meet the requirements of low-cost,rapid manufacturing and environmental friendliness.Therefore,continuous ramie fiber-reinforced polylactic acid(PLA)-based biomass composites with different layups were manufactured by in-situ impregnated 3D printing process.The quasi-static penetration test was conducted to evaluate the effects of layup configuration,support span to indenter diameter ratios(SIRs)and fiber reinforcement on the penetration property of the composites.The damage evolution behavior of the composites during the penetration process was captured in real time by the backlight method.The results show that the addition of continuous ramie fiber increased the penetration strength of the composites by 51.5%(unidirectional)and 52.9%(orthogonal).Compared with the unidirectional layup,the composite with orthogonal layup had an increase of 24.9%and 13.1%in the absorbed energy and maximum penetration force,respectively.The penetration property of the printed sample increased significantly with the decrease of the SIR.The orthogonal layup composite had an increase of 202.4%in strength when the SIR was 10 compared to when the SIR was 5.Finally,the relationship between the layup structure and penetration property of 3D printed composites was revealed through the multiscale analysis of failure features and penetration damage mechanisms.