Buckling load and part weight optimization of mild carbon fiber reinforced PLA parts

Fused Deposition modeling has gained more attention in making of end use products from thin thermoplastic filaments through material extrusion technique. The current study involves optimizing four different input parameters such as Infill Density (30%, 60% and 90%), Part orientation (Flat, on edge and Upright), Infill pattern (Grid, Octet and Gyroid) and Shell thickness (0.8mm, 1.2mm and 1.6mm) for reducing part weight and improvement of buckling load for PLA with 8% (Mild) carbon fiber reinforcement. Nine different experiments have been conducted using taguchi’s experimental design layout and experimental values are further analyzed through Entropy and CRITIC methods. Multi criteria decision making method TOPSIS ranked the alternatives for obtaining reduced weight and enhanced bucking load. The ranking of alternatives varied with respect to the criteria weight determining method. TOPSIS–ENTROPY method recommends 60% infill density, Flat part orientation, Octet infill pattern and 1.6mm shell thickness and TOPSIS –CRITIC method suggests 30% infill density, On edge part orientation, Octet infill pattern and 1.2 mm shell thickness. In comparison the combination recommended by TOPSIS – ENTROPY is found to be better with moderate part weight of 14 gms and higher buckling load capacity of 4KN than TOPSIS –CRITIC method recommended part weight of 10 gms and 2.6 KN buckling load. The method adopted for criteria weight determinations shows a significant influence over the ranking of alternatives in a considerable manner.