Infill Toolpath Optimization for Fused Deposition Modeling Based on Principal Stress Lines

Abstract:

Anisotropy in strength between layers and filaments in fused deposition modeling （FDM） additive manufacturing has a significant influence on mechanical properties of fabricated objects. A method was proposed to improve mechanical properties of the part by the design of the infill toolpath to make it in alignment with the load paths under the guidance of principal stress lines （PSL）. The PSL generation method based on finite element analysis and the PSL visualization method based on Grasshopper were presented. The region toolpath generation algorithm based on PSL seed lines and the toolpath-to-Gcode conversion method were put forward. Tensile and three-point bending mechanical tests were carried out. Compared with the traditional infill toolpaths in the 0°and 90° direction， the tensile strength of the PSL-based printed specimens increased by 8.33% and 19.74%， and the bending strength of the PSL-based printed specimens increased by 11.46% and 20.47%， respectively.