Sustainable Design-Oriented Level Set Topology Optimization

Abstract

This paper presents a novel sustainable design-oriented level set topology optimization method. It addresses the sustainability issue in product family design, which means an end-of-life (EoL) product can be remanufactured through subtractive machining into another lower-level model within the product family. In this way, the EoL product is recycled in an environmental-friendly and energy-saving manner. Technically, a sustainability constraint is proposed that the different product models employ the containment relationship, which is a necessary condition for the subtractive remanufacturing. A novel level set-based product family representation is proposed to realize the containment relationship, and the related topology optimization problem is formulated and solved. In addition, spatial arrangement of the input design domains is explored to prevent highly stressed material regions from reusing. Feature-based level set concept for sustainability is then used. The novelty of the proposed method is that, for the first time, the product lifecycle issue of sustainability is addressed by a topology optimization method. The effectiveness of the proposed method is proved through a few numerical examples.

Hip Implant Design With Three-Dimensional Porous Architecture of Optimized Graded Density

“…To solve the largescale 3D problem, we use a recently introduced scheme for topology optimization, the proportional topology optimization (PTO) [37], to minimize one objective function, i.e., bone resorption, and convert the other, i.e., bone-implant interface failure, into a design constraint that prevents bone-implant micromotion. PTO is a gradient-free method chosen here over other stochastic and gradient-based methods, such as solid isotropic material with penalization SIMP [38][39][40][41] and level set [42][43][44][45], for its simplicity and efficiency. While PTO does not require to calculate the sensitivity of objective function and constraints [46], it does preserve the flexibility to design for intermediate densities, a factor that is relevant to the problem examined here.…”

Current and future trends in topology optimization for additive manufacturing

“…As an alternative solution, Liu and To [49] developed an overhang-free level set topology optimization method, where each level set function corresponds to a printing layer (or a bundle of layers with the same cross-section shape) and a novel multi-level set interpolation was proposed to constraining the spatial relationship of consecutive printing layers to avoid the overhang features. Then, the optimization problem can be solved similar to other multi-level set topology optimization problems [50][51][52][53]. Besides the layer-by-layer idea, Guo et al [23] realized the self-support design through two explicit approaches: constraining the bar component angles of the MMC (Moving Morphable Components) method [54] and using self-support B-spline void representation of the MMV (Moving Morphable Voids) method [55].…”

A Topology Optimization Method for Hybrid Subtractive–Additive Remanufacturing

“…As we can see from the literature survey, topology optimization has never been implemented targeting the remanufacturing problems or subjected to the hybrid subjective-additive manufacturing background. An exception was found in [43], where the sustainable design through topology optimization was achieved; however, only the conceptual idea was explored but the involved manufacturing techniques were not specified. Hence, the main contribution of this paper is the new topology optimization algorithm for hybrid subtractive-additive remanufacturing, which is theoretically novel and practically meaningful.…”

“…The detailed sensitivity analysis process is not demonstrated. Interested readers can refer to the classic works [43,46,47]. The derived sensitivity result is shown below: Therefore,…”