Experimental Calibration of Randomness in Additively Manufactured Continuously Reinforced Composites

Abstract

This paper presents an experimental analysis of the uncertainty in physical and mechanical properties of fused filament fabrication (FFF) parts that are reinforced with continuous carbon fibers (CCF). The goal of this work is to quantify modulus uncertainty in composites specimens printed on a commercially available continuous carbon filament 3D printer. The specimens that are analyzed in this paper are fabricated of a nylon-based material as the thermoplastic matrix and CCF as the reinforcing material. The test specimens are designed with four unique set of stacking sequences, which are categorized as SS #1, a combination of symmetric 0°and 90°layers, SS #2, a combination of symmetric ±45°layers, SS #3, a combination of symmetric 0°, ±45 °, and 90°and SS #4, a combination of non-symmetric ±45°layers. In each category, a total of 15 specimens are manufactured through FFF. A load-unload tensile test is performed for each specimen using an extensometer and digital image correlation (DIC) for strain analysis. Elastic Modulus (Exx) values of the specimens are determined and compared within each specimen to analyze the uncertainty. Also, strain variability is analyzed among the specimens using the DIC results.