Theory and Methodology for High-Performance Material-Extrusion Additive Manufacturing Under the Guidance of Force-Flow

Abstract

Anisotropy on strength between different layers and filaments in the material extrusion (MEX) process has a significant influence on mechanical performances of fabricated objects. A novel theory and methodology is proposed to improve mechanical performances of parts by designing and controlling the anisotropy. Anisotropy can then be in alignment with load paths under the guidance of force-flow. In this study, by (1) dividing the part into several building areas and generating corresponding building direction considering the force-flow properties of the part; (2) generating novel toolpaths which are based on principal stress lines (PSL) and will map the direction and magnitude of PSL, the adverse influence of anisotropy on mechanical performances between different layers and filaments can be minimized respectively. A 6-axis robot arm integrated with an extrusion system is constructed to handle the multi-direction building of each building area. The study will advance the development of additive manufacturing from "prototype" to "end-use".