Research On Additive Manufacturing Process Of Shape Memory Carbon Fiber Composite Lenticular Tube

With the vigorous development of the aerospace industry,various space folding mechanisms have been widely used in the aerospace field due to their advantages of being freely retracted,and they have received more and more attention.They can maintain small in size when launched,and deploy in a specified state after being launched into space,effectively overcoming the limitations of the spacecraft on the volume of the mounted object.Compared with the complex traditional mechanical folding mechanism,the application of smart materials in this field has shown great development potential in recent years.The smart material folding mechanism s have the advantages of simple structure,light weight and high reliability.The lenticular tube studied in this paper belongs to one of the tubular stretching mechanisms,and has a large storage ratio and a large expansion rigidity,which is generally made of carbon fiber composite material.The traditional carbon fiber composite material preparation process is very complex,requiring large equipment and high mold cost.To solve this problem,smart materials and additive manufacturing methods are combined in this paper to manufacture shape memory composite lenticular tube by 3D printing,which has the advantages of low cost and high molding efficiency,and provides a new idea for the preparation process of carbon fiber composite materials.In this paper,the 3D printing method of continuous fiber reinforced shape memory polymer(SMP)composites was studied.The structural design of the composite printing nozzle was optimized,and the printed specimens with better surface quality and better mechanical properties were obtained.The control variable test and orthogonal test design were used to characterize the microscopic interface and macroscopic mechanical properties.The 3D printing process parameters of the composite were systematically studied to obtain the best printing process parameters.In addition,the glass transition temperature(Tg)of the 3D printed composites was obtained by dynamic thermomechanical analysis.The effect of fiber content and ply angle on the shape memory effect of SMP was studied by the bending recovery experiment of shape memory polymer composites.The digital image correlation(DIC)was used to test the strain of the composite during shape recovery.In this paper,the genetic algorithm was used to optimize the cross-sectional shape and size of the lenticular tube,which layed a foundation for the 3D printing.The shape memory process simulation of the material layer was carried out by using ABAQUS software to analyze the stress in the shape memory process.Finally,using the optimal printing parameters,the 3D printing of the lenticular tube structure was carried out.The mechanical properties of the 3D printed lenticular tube were analyzed by compression and bending tests,and the bending recovery test was carried out to verify the shape memory function.The bending modulus of the 3D printed continuous fiber reinforced shape memory composite prepared in this paper can reach 7.13 GPa,which is 7.6 times higher than that of 3D printed pure SMP material,which can solve the problem that the SMP material is limited in engineering due to poor mechanical properties.The shape memory composite lenticular tube was successfully fabricated by 3D printing,which can break the limitation of the mold and verify the feasibility of this process.