Infill Optimization for Additive Manufacturing -- Approaching Bone-like Porous Structures

TL;DR

This paper introduces a voxel-wise topology optimization method to generate lightweight, bone-like porous structures for additive manufacturing, enhancing mechanical properties while maintaining stability.

Contribution

It extends voxel-wise topology optimization with localized volume constraints aggregated via p-norm, enabling efficient creation of natural, porous structures within given shapes.

Findings

Generated detailed, mechanically optimized porous structures.

Demonstrated robustness and adaptability of the method.

Produced structures that closely mimic natural bone porosity.

Abstract

Porous structures such as trabecular bone are widely seen in nature. These structures exhibit superior mechanical properties whilst being lightweight. In this paper, we present a method to generate bone-like porous structures as lightweight infill for additive manufacturing. Our method builds upon and extends voxel-wise topology optimization. In particular, for the purpose of generating sparse yet stable structures distributed in the interior of a given shape, we propose upper bounds on the localized material volume in the proximity of each voxel in the design domain. We then aggregate the local per-voxel constraints by their p-norm into an equivalent global constraint, in order to facilitate an efficient optimization process. Implemented on a high-resolution topology optimization framework, our results demonstrate mechanically optimized, detailed porous structures which mimic those found in nature. We further show variants of the optimized structures subject to different design specifications, and analyze the optimality and robustness of the obtained structures.