Multi-objective Strength Optimization of Fused Filament Fabricated Complex Flexible Parts Using Grey Relational Analysis

The process parameters associated with the additive manufacturing process played a major role in defining the properties of fabricated object. The present study investigates the effect of three different process parameters, i.e. extrusion temperature, layer thickness and build orientation, on tensile strength, compressive strength and hardness of thermoplastic polyurethane (TPU) material printed through fused filament fabrication (FFF) process. Taguchi orthogonal array has been used for the design of experiment. Grey relational analysis has been applied to combine these three targets into one to get the optimum combination of process parameters. Extrusion temperature of 200 degrees C, layer thickness of 0.2 mm and build orientation of 0 degrees have been found as the optimal process parameters for maximizing the mechanical properties of TPU parts. A body-centred cubic lattice structure has been successfully printed as a case study to determine the suitability of investigated process parameters for fabrication of complex flexible parts using the FFF process.