连续碳纤维3D打印圆形增强蜂窝的面内压缩性能

In-plane compression properties of 3D printed continuous carbon fiber circular improved honeycomb

为提高圆形蜂窝(CH)的抗压缩性能和吸能性能,以CH结构为基础,在横向和竖向上增设树叶形支撑,提出了单向增强圆形蜂窝(SEH)和双向增强圆形蜂窝(DEH)两种改进型蜂窝。以碳纤维(CF)作为增强体,聚乳酸(PLA)为基体,使用连续纤维3D打印技术制造了试验件,并规划结构内部CF的成型路径,同时设置PLA对照组。通过准静态压缩试验研究各蜂窝的面内压缩性能、吸能特性和结构的变形失效模式。结果表明:CF增强后的DEH-CF相较CH-CF在比吸能上提升167.63%。CH、SEH和DEH在采用CF增强后,比吸能相比PLA对照组分别提高43.37%、63.17%和161.58%,平均压缩力分别提高51.72%、61.81%和96.09%。研究发现,CF增强结构内部的纤维路径规划会影响结构的刚度和变形行为,采用“支撑一体化成型”路径的DEH-CF在压缩时,其结构动态泊松比保持在PLA对照组33.36%以下。

To improve the compression resistance and energy absorption performance of circular honeycomb(CH),two improved honeycomb,single enhanced circular honeycomb(SEH)and double enhanced circular honeycomb(DEH)were designed on the basis of CH structure,and leaf shaped supports were added horizontally and vertically.Using carbon fiber(CF)as reinforcement and polylactic acid(PLA)as matrix,continuous fiber 3D printing technology was used to manufacture test parts,and the forming path of CF bundle inside the structure was designed,PLA control group was set.The in-plane compression properties,energy absorption characteristics and deformation failure modes of the honeycomb structures were investigated by quasi-static compression tests.The results show that the specific energy absorption(SEA)of CF enhanced DEH-CF is improved by 167.63%compared with CH-CF.The SEA are increased by 43.37%,63.17%and 161.58%and mean crushing force are increased by 51.72%,61.81%and 96.09%compared with the PLA control group,respectively.The results indicate that the fiber path planning inside the CF reinforced structure would affect the stiffness and deformation behavior of the structure.The dynamic Poisson's ratio of the DEH-CF using the"strut integrated molding path"during compression remains 33.36%lower than that of the PLA control group.