Research On 3D Printed Fiber Reinforced Composites Process Optimization And Automobile Honeycomb Energy Absorption Properties

3D printing technology has been applied in automotive design and part molding due to its unique characteristics,which can manufacture components with complex shapes in a shortened production cycle without molds.However,low mechanical strength,limited options of consumables,and high cost of manufacturing have greatly restricted the development and application of 3D printing technology.The aim of current work was to develop and test a newtype short carbon fiber reinforced nylon 6(CF/PA6)composite printing filament via fused deposition modeling(FDM)printing method.The thermal and mechanical performance of composite filaments have been evaluated,and the printing parameters and post-processing parameters were further optimized.Using an optimized fiber content and processing parameters,the filament was then used to manufacture the re-entrant honeycomb.In-plane compression behavior of the honeycomb was assessed,and the rebound and energy absorption ability of CF/PA6 honeycomb were investigated.The main contents of our study were as follows:(1)Developing a new-type CF/PA6 composite printing filament for the FDM printing method.The effects of CF content on the mechanical and thermal properties of the composite filament have been analyzed.The experimental results showed that the addition of CF significantly improves the extrusion stability of the filament.It was also found that the tensile properties mechanics performance show a trend of increasing first then decreasing when the CF content increaseed from 0 to 15%.It was determined that CF10/PA6 exhibited a superior mechanical performance.The crystallization temperature of CF/PA6 filament slightly increased,while the thermal decomposition temperature remained unchanged.(2)Exploreing the processing parameters of CF/PA6 composite filament.The effects of printing direction,build-plate temperature and post-treatment temperature on mechanical properties and interlayer adhesion were evaluated.The results showed that the 0° printing direction was beneficial to the fiber orientation,thereby improved the mechanical performance of FDM-printed samples.As the temperature of the build-plate temperature increased,the interlayer bonding strength of printing layers improved.The post-processing temperature at 130? enhanced the mechanical performance of FDM-printed CF/PA6..(3)Designing a re-entrant honeycomb of CF10/PA6 via FDM printing.The in-plane compression behavior and energy absorption capacity were investigated.The results showed that during the in-plane compression,the honeycomb periodically folded left and right with the increase of compressive strain.There was no obvious fracture failure between the honeycomb layers.The printed re-entrant honeycomb exhibited a good in-plane compression rebound effect.As the compression strain increased,the honeycomb rebound displacement increased.Moreover,increased compressive strain resulted in decreased post-compression stress and energy absorption,while compression numbers have no significant influences on these two factors.The research on this paper has certain guiding significance for the preparation,molding process and deformation energy absorption and resilience of 3D printed CF/PA6 composite filaments.