Multi-objective optimisation of strength and volumetric shrinkage of FDM parts

Abstract

In the present work, the relationships between two important quality objectives, namely, strength and volumetric shrinkage of fused deposition modelling (FDM) parts and selected process parameters, namely the build interior, the horizontal build direction and the vertical build have been determined through a minimum number of experiments based on face centred central composite design. Specimens have been manufactured on an FDM machine and tests have been conducted to evaluate strength and volumetric shrinkage. The relationship for each of these two response variables in terms of the three process parameters has been constructed using analysis of variance. The resulting two objective functions are optimised simultaneously using the non-dominated sorting genetic algorithm. In order to validate the Pareto optimal solution, three randomly chosen experimental runs at intermediate parameter values (other than design of experiments levels) were repeated and good correlation was found between these results and the Pareto optimal.