Using finite element analysis to influence the infill design of fused deposition modelled parts

Abstract

Additive manufacturing (AM) has and continues to experience considerable market and technological growth with many forecasting a tripling in market value over the next decade. One of the primary drivers for this growth is the increased freedom afforded to the design of both the external form and internal structure of fabricated parts. This freedom presents greater opportunities in optimising a parts mechanical properties, (such as strength, stiffness and mass), which in turn leads to enhanced performance whilst potentially reducing material use and hence, environmental impact. Realising this potential will further increase the viability of AM for a greater range of engineering contexts. Correspondingly, the contribution of this paper lies in the creation and validation of a method for the topological optimisation of the infill structure of fused deposition modelled (FDM) components. The proposed method uses results attained from finite element analysis (FEA) to influence the design of the internal structure (i.e. infill) by locally varying the composition of the infill based upon the associated stress values. This paper presents and discusses the proposed method, and demonstrates the generalisability of the method through its ability to handle complex geometries and loading conditions, and manufacturing process constraints. In addition, the paper validates the method through testing of FDM beams comprised of FEA influenced and standard honeycomb infill designs undergoing four different loading scenarios. The validation reveals that a three and a half times increase in strength can be achieved where the stress profiles are well defined within the structure. In addition, the FEA-influenced beams exhibited more consistent failure mode profiles, which maybe desirable for designing parts with specific failure mode characteristics.

Infill Design Reinforcement of 3D Printed Parts Using Refinement Technique Adapted to Continuous Extrusion

“…According to this refinement technique, the objective was to subdivide infill design in such a way that continuous printing constraint is satisfied while increasing the strength of the part. In hindsight, like the work in [12,17], we suspect it could bring benefits to place the material as infill along the stress field direction during the refinement. Some of the ideas that we will address concerning the present refinement methodology as future works are: Adding the capability to align the infill along the stress field by moving the nodes of the elements of infill design.…”

“…This proved that placing material in the direction of principal stress truly could help to reduce material usage and increase the stiffness of the part. In another study, the same authors [17] have proposed a method using the results of finite element analysis (FEA) to influence the internal geometry of components. A rectangular part undergoing different loading scenarios has been studied.…”

Multi-resolution in architecture as a design driver for additive manufacturing applications

“…Locally controlling filament deposition during FDM by the application of FEA models has shown successful transformation of mechanical properties. 21…”

Scrappy: Using Scrap Material as Infill to Make Fabrication More Sustainable

“…For example, systems from Mueller et al [19] and Peng et al [22] approximate the objects' surface, by printing a wireframe version of the geometry, but this reduces fdelity and is therefore only applicable for certain kinds of rapid prototyping. If object detail is important, material consumption can be reduced by optimizing the required infll to support all exterior walls of the object [14], or to optimize only for expected loads [11,26]. Our system follows a diferent approach to reduce infll and can be applied in conjunction with infll optimization for even greater material savings.…”