Arbitrary void feature control in level set topology optimization

Feature-driven topology optimization has been extensively studied in the past decade, and the majority of the works have treated it as the multi-component/void layout optimization problem. A major limitation of this treatment is that the number of components/voids should be defined in advance. To overcome this limitation, this paper presents a novel void feature control method, through which the specified void feature (in any geometric form) could be well-contained by each interior void in the finalized topology design, regardless of the quantity. Numerical stability of this method is discussed and an auxiliary algorithm has been developed to enhance it. Other than that, the proposed method also serves the purpose of void length scale control, which is also a hot issue in the topology optimization field. To be specific, by tailoring the specified void feature size, the void length scale is guaranteed to be larger than that. To the authors' knowledge, the void length scale control was rarely studied under the level set framework. Through a few numerical case studies, it is proven that the void feature control method is effective while only limited compromise of the structural performance has been observed.