连续纤维增强复合材料变刚度结构3D打印与性能研究

Continuous fiber reinforced variable stiffness composite structures can adjust fiber content and direction distribution to maximize fiber performance advantages. However, the existing manufacturing process is difficult to precisely control the fiber content. The mapping relationship between process parameters and fiber content is established based on 3D printing of the continuous fiber reinforced composites. The integrated manufacturing of continuous fiber reinforced variable stiffness composite structures is achieved by dynamically adjusting the feed ratio of resin during the 3D printing process. The influence of the variable stiffness distribution of fiber content on the bending and impact properties of the part is systematically studied. The flexural modulus and impact strength of the 3D printed variable stiffness structures are respectively 70% and 65% higher than that of the homogeneous structures under the same average fiber content. The failure behavior of 3D printed continuous fiber reinforced variable stiffness composite structures is analyzed by constitutive models of 3D printed composites with different fiber content. The results show that the resistance of the part to fiber tensile damage will increase by setting a higher fiber content on the back side of the part, and the load-bearing capacity of the part and the use efficiency of the fiber will be greatly improved. The research in this paper provides new ideas for the design and manufacture of composite materials in the aerospace, rail transit and other fields.