Multi-objective parametric optimization for manufacturing structures with gradients in additive manufacturing

Abstract

While Fused Deposition Modeling (FDM) technology offers the advantages of low manufacturing costs and the capability to produce a diverse range of products, it still presents several challenges. This study specifically addresses the difficulties associated with printing structures containing gradients. When printing overhanging geometries or gradients that exceed a certain angle, support structures are essential. These structures can result in issues such as extended build time, increased post-processing costs, and material wastage, negatively impacting productivity and efficiency. This contrasts with the advantages of 3D printers, which can produce a variety of geometries in a rapid production process, which has a critical effect on the manufacturing process. Therefore, this experiment aims to derive the optimal parameters for printing products with gradients without bottom support in FDM manufacturing to improve economy and efficiency while simultaneously satisfying product quality, printing time, and product durability. FDM technology is based on extrusion technology using thermoplastic materials, and as such, various parameter settings have a significant effect on the quality of the product. The main parameters for the experiment were selected based on preliminary experiments. The gradient angle for printing the specimen was set to an angle where the effect on quality could be confirmed under different parameter conditions. The experiment utilized the Taguchi Method to construct the printing conditions, followed by multi-objective optimization to optimize the printing parameters. The evaluation criteria included the surface roughness of the bottom of the gradient, printing time, and product strength. For the analysis of the results, the Utility analysis method was performed in an integrated approach, using Principal Component Analysis (PCA) to give relative weights to the different response characteristics considering their purpose. This facilitated the identification and analysis of key parameters for the successful printing of products with gradients. Analysis of Variance (ANOVA) was used to assess the contribution of each parameter to all purposes combined to identify the dominant factors and evaluate their relationship. Finally, a validation test was performed to verify the validity of the proposed approach. The outcomes of this study are anticipated to significantly contribute to the advancement of extrusion-based additive manufacturing technology, thereby paving the way for the realization of efficient and economical production in the manufacturing industry.