A practical review on promoting connectivity in topology optimization

TL;DR

This paper reviews various connectivity constraints in topology optimization, comparing their effectiveness and practical implications for designing manufacturable, high-performance structures, especially in sandwich panels balancing acoustic and structural needs.

Contribution

It provides a comprehensive overview and practical comparison of five connectivity constraints, offering insights and guidelines for their effective application in topology optimization.

Findings

Connectivity constraints significantly influence design outcomes.

Practical comparison reveals trade-offs in computational cost and performance.

Guidelines for selecting appropriate constraints are provided.

Abstract

Topology optimization facilitates the automated design of high-performance structures across various engineering fields but, if unconstrained, often produces designs that are complex and difficult to manufacture. A key attribute of the resulting designs is connectivity, which involves controlling the presence of solid and/or void islands of material. This manuscript provides a comprehensive overview of existing connectivity constraints developed for continuous design representations and highlights their advantages and limitations in influencing design outcomes and performance. The review further includes a practical comparison of five different connectivity constraints using a topology optimization framework for sandwich panels that balances acoustic and structural performance. With Pareto-front analyses, the constraints are evaluated based on computational cost, monotonicity, parameter dependency, and their impact on the optimized designs, their performance, and underlying dynamics. From the comparison, practical insights and rule of thumbs have been derived. The findings emphasize the critical role of selecting appropriate connectivity constraints, given their significant effect on the optimization results.