EXPERIMENTAL AND STATISTICAL OPTIMIZATION OF CARBON-FIBER REINFORCED NYLON COMPOSITE BASED 3D PRINTED CELLULAR STRUCTURES

The development of advanced composite materials in the recent years has changed numerous aspects of the manufacturing sector. These advanced composite materials showed the potential to replace high-performance alloys at extremely competitive costs. Additive manufacturing gained popularity in the industry due to the ability to print complex shapes. As per existing literature cellular geometry has a controlling influence on the mechanical behavior, and it can be employed to have tunable mechanical properties. Onyx (TM) is a composite material comprised of nylon mixed with chopped micro-carbon-fiber. For this study, 3D printed nylon-carbon fiber reinforced composite specimens were fabricated using a high-end Markforged (R) X7 (TM) printer. The study aimed to experimentally investigate the Young's modulus, ultimate tensile strength, and toughness of the 3D printed nylon-carbon fiber composites having cellular geometry structure. The study investigated different cellular geometry patterns, strain rates and layer heights. Taguchi assisted design of experiment was utilized. To reach reasonable conclusion, a multi objective optimization technique known as grey relational analysis was utilized. Parameters should be optimized in to have proper melting of filament and material solidification. It was found that the optimal parametric condition was diamond horizontal infill pattern, strain rate of 1 mm/ min and a layer height of 0.1 mm. It was observed that sensitivity of 3D printed cellular materials significantly controls the quality of the specimens.