Defect analysis and quality evaluation system for additive manufactured continuous fiber-reinforced polymer composites

Abstract

The combination of continuous fiber-reinforced polymer composites (CFRPCs) and additive manufacturing (AM) offers a solution for the integrated manufacturing of high-performance, complex structures, but due to current process limitations, various defects exist within the parts. Most research has focused on internal pores defects and mechanical properties but lacks in-depth studies on the mechanisms of other defect forms and comprehensive quality evaluation systems. To address these gaps, this paper applied comprehensive parameter analysis, visualization techniques, rheological experiments, and mechanical experiments to systematically explore the effects of defects on the printing quality of AM-CFRPCs, focusing on shape fidelity, surface accuracy, structural integrity, and mechanical performance. Targeted improvement measures were proposed for various defects, effectively eliminating shape-related issues such as fiber slippage, fillet, first layer accumulation, and warpage, leading to a high-quality deposited surface with low roughness and waviness, as well as an internal structure with low porosity. Furthermore, a comprehensive molding quality evaluation system was established, offering a reliable framework for part quality assessment. Additionally, the variation patterns of the key-like profile cross-sections of the single path under different layer heights were summarized, and precise calculation models for path width and overlap ratio were presented. Consequently, this paper delivers detailed guidelines for enhancing molding quality to facilitate the production and evaluation of high-quality AM-CFRPCs.