Additive manufacturing of continuous fiber reinforced composites with variable volume fractions

This study presents a novel approach to additive manufacturing for Continuous Fiber Reinforced Composites (CFRCs), featuring an adjustable nozzle, enabling variable volume fraction control of continuous fibers. By modifying the dimensions of the print head, this method allows for a seamless adjustment of the continuous fiber volume fraction, ranging from 3.6% to 32%, throughout the fabrication process. Concurrently, an optimization method for the printing path, grounded in the analysis of principal stress trajectories, has been developed. This algorithm has been rigorously validated through advanced simulation techniques, proving its efficacy in enhancing the mechanical properties of the fabricated specimens. Subsequent experimental validation using the developed equipment resulted in a 61.04% increase in tensile strength, without any increase in fiber content, thereby highlighting the efficiency of the developed process. The study confirms the potential of this strategy in advancing composite material technology for complex part manufacturing with improved mechanical performance. The equipment also promises to produce a greater number of high-quality printed samples with optimized paths.