PDF(Pubmed)
Abstract：
Characterized by light weight and high strength, composites are widely used as protective materials in dynamic impact loading under extreme conditions, such as high strain rates. Therefore, based on the excellent tensile properties of continuous fiber and the good flexibility and toughness of the bionic spiral structure, this study uses a multi-material 3D printer to incorporate continuous fiber, and then modifies the G-CODE file to control the printing path to achieve the production of a continuous fiber-reinforced Polylactic Acid composite helicoidal (spiral angle 60°) structure (COF-HP). Dynamic behavior under high-strain-rate impact experiments have been conducted using the Split Hopkinson Pressure Bar (SHPB). Stress-strain curves, impact energy curves and high-speed camera photographs with different strain rates at 680 s-1 and 890 s-1 have been analyzed to explore the dynamic process and illustrate the damage evolution. In addition, some detailed simulation models considering the incorporation of continuous optical fiber (COF) and different strain rates have been established and verified for deeper investigations. The results show that the COF does enhance the impact resistance of the laminates. When the porosity is reduced, the maximum stress of the continuous fiber-reinforced composite material is 4~7% higher than that of the pure PLA material. Our findings here expand the application of COF and provide a new method for designing protective materials, which have broad application prospects in the aerospace and automotive industries.
摘要：
具有重量轻、强度高的特点，复合材料被广泛用作极端条件下动态冲击载荷的防护材料,如高应变率。因此,基于连续纤维优异的拉伸性能和仿生螺旋结构良好的柔韧性和韧性，这项研究使用多材料3D打印机来整合连续纤维，然后修改G-CODE文件以控制印刷路径，以实现连续纤维增强聚乳酸复合螺旋（螺旋角60°）结构（COF-HP）的生产。使用分离式霍普金森压杆（SHPB）进行了高应变率冲击实验下的动态行为。应力-应变曲线,分析了680s-1和890s-1下不同应变速率的冲击能量曲线和高速相机照片，以探索动力学过程并说明损伤演化。此外,一些详细的模拟模型考虑了连续光纤（COF）和不同的应变率已经建立和验证更深入的研究。结果表明，COF确实提高了层压板的抗冲击性。当孔隙率降低时，连续纤维增强复合材料的最大应力比纯PLA材料高4~7%。我们的发现扩展了COF的应用，为设计防护材料提供了一种新的方法，在航空航天和汽车工业中具有广阔的应用前景。
