Robust optimal component design under consideration of local material defects

TL;DR

This paper presents a robust optimization method for component design in additive manufacturing that accounts for local material defects by considering worst-case material variations to enhance reliability.

Contribution

It introduces a worst-case robust optimization framework for component layout considering local material uncertainties, with a gradient-based algorithm for solution.

Findings

The method improves component reliability under material defects.

Numerical results demonstrate the effectiveness of the robust design approach.

The approach enhances insensitivity to local material variations.

Abstract

An important issue in additive manufacturing is the reliability and reproducibility of parts. One major problem in achieving this are uncontrolled local variations in the obtained material properties which arise in the complex manufacturing process and are usually not taken into account in the design of components. We consider the optimal layout of a part to withstand a given loading, under the assumption that the local material properties are not precisely known. The material uncertainties are treated by a worst case approach. This means that for each layout a given amount of defects in material properties is distributed in the design domain, such that the stiffness of the component is maximally weakened. As a consequence, an optimization result is obtained which is as insensitive as possible with respect to unknown variations in the material parameters. The general model is introduced and an algorithm for its solution using gradient based methods is suggested. Finally, numerical results are presented and discussed.