TOBACO: Topology Optimization via Band-limited Coordinate Networks for Compositionally Graded Alloys

TL;DR

This paper presents a novel topology optimization framework for designing Compositionally Graded Alloys using band-limited coordinate neural networks, enabling controlled material gradation and high-resolution, mesh-independent designs.

Contribution

It introduces a neural network-based method that implicitly enforces gradation constraints in CGA design, improving upon traditional explicit constraint approaches.

Findings

Effective control of compositional gradation in CGAs.

Mesh-independent, high-resolution design extraction.

Demonstrated success in elastic and thermo-elastic optimization examples.

Abstract

Compositionally Graded Alloys (CGAs) offer unprecedented design flexibility by enabling spatial variations in composition; tailoring material properties to local loading conditions. This flexibility leads to components that are stronger, lighter, and more cost-effective than traditional monolithic counterparts. The fabrication of CGAs have become increasingly feasible owing to recent advancements in additive manufacturing (AM), particularly in multi-material printing and improved precision in material deposition. However, AM of CGAs requires imposition of manufacturing constraints; in particular limits on the maximum spatial gradation of composition. This paper introduces a topology optimization (TO) based framework for designing optimized CGA components with controlled compositional gradation. In particular, we represent the constrained composition distribution using a band-limited coordinate neural network. By regulating the network's bandwidth, we ensure implicit compliance with gradation limits, eliminating the need for explicit constraints. The proposed approach also benefits from the inherent advantages of TO using coordinate networks, including mesh independence, high-resolution design extraction, and end-to-end differentiability. The effectiveness of our framework is demonstrated through various elastic and thermo-elastic TO examples.