Some principles to optimise an additively manufactured multi-component product

Abstract

Depending on the requirements, the design of a product may result in very different solutions. Topological optimization is a mathematical tool that can be used to obtain lighter parts without decreasing their stiffness. As the optimized part shapes are often too complex to be manufacturable, additive manufacturing is generally used. Usually, the topological optimization is performed on a single part. However, for a product, the decreasing of mass and inertia in each individual part has an impact on the loads applied onto all the parts of the system. Moreover, different paths can be used to optimize a product, e.g. optimizing all the parts simultaneously or part after part. Therefore, the aim of this paper is to propose, based on a case study, some optimization principles to find the best optimization path to design an additively manufactured product. In order to do this, the concept of topological optimization loops is first proposed. Then, several optimization paths are compared. In comparison with a usual single topological optimization, the proposed method leads to an additional gain in mass of up to 35% for the case study. Finally, some optimization principles are suggested to choose the most adapted path according to the designer objectives.

Topological Optimization of a Mechanical System with Adaptive Convergence Criterion

“…The Topological Optimization of a Mechanical System (TOMS) corresponds to the topological optimization of each rigid body of a mechanical product by taking into account the impacts of optimizations between the rigid bodies. This method was recently proposed and is more detailed in [8,9].…”

“…In the study carried out in [8], a unique value of ε was set at 0.1, which leads to carry out a certain number of optimization loops on the parts as shown in Table 1 for path 1 and 2.…”

“…In this case, the value of the coefficient of convergence should be close to 0.1. In the article [8], a third path where all part are simultaneously optimized was also proposed. It can be noted that, for this path, the variation of the convergence coefficient is not applicable.…”

“…However when the mass has an important influence on the mechanical behavior, new boundary conditions have to be taken into account. Our method called TOMS (Topological Optimization of a Mechanical System) and presented in detail in [8] is one of the firsts for designing a mechanical product taking into account this aspect. For this, optimization loops have been developed.…”

An Assembly-Oriented Design Framework for Additive Manufacturing

“…Nevertheless, a few contributions [8][9][10][11][12] are targeted at conceptual design for AM. Furthermore, the few assembly-oriented DFAM (A-DFAM) contributions do restrict the scientific issues to part consolidation (PC) [13]. These two aforementioned situations are fully encapsulated in Yang et al's [11] statements: '[A-DFAM] mainly focuses on the redesign of assemblies by taking advantage of AMenabled capabilities .…”