Stress Flow Guided Non-Planar Print Trajectory Optimization for Additive Manufacturing of Anisotropic Polymers

TL;DR

This paper presents a novel trajectory optimization method for additive manufacturing of anisotropic polymers, aligning print paths with stress flows to significantly enhance mechanical strength and stiffness.

Contribution

It introduces a non-planar slicing and trajectory optimization framework that considers manufacturability constraints and stress alignment for improved part performance.

Findings

Failure strength increased by 44 times

Stiffness improved by 6 times

Validated on a 5-axis 3D printed bracket

Abstract

When manufacturing parts using material extrusion additive manufacturing and anisotropic polymers, the mechanical properties of a manufactured component are strongly dependent on the print trajectory orientation. We conduct non-planar slicing and optimize the print trajectories to maximize the alignment between the material deposition direction and the stress flow induced by a predefined load case. The trajectory optimization framework considers manufacturability constraints in the form of uniform layer height and line spacing. We demonstrate the method by manufacturing a load bearing mechanical bracket using a 5-axis 3D printer and a liquid crystal polymer material. The failure strength and stiffness of the optimized bracket are improved by a factor of 44 and 6 respectively when compared with conventional printing.