Olivier Kerbrat

A new DFM approach to combine machining and additive manufacturing

Design for manufacturing (DFM) approaches aim to integrate manufacturability aspects during the design stage. Most of DFM approaches usually consider only one manufacturing process, but product competitiveness may be improved by designing hybrid modular products, in which products are seen as 3-D puzzles with modules realized individually by the best manufacturing process and further gathered. A new DFM system is created in order to give quantitative information during the product design stage of which modules will benefit in being machined and which ones will advantageously be realized by an additive process (such as Selective Laser Sintering or laser deposition). A methodology for a manufacturability evaluation in case of a subtractive or an additive manufacturing process is developed and implemented in a CAD software. Tests are carried out on industrial products from automotive industry.

A new global approach to design for additive manufacturing

Nowadays, due to rapid prototyping processes improvements, a functional part can be built directly through additive manufacturing. It is now accepted that these new processes can increase productivity while enabling a mass and cost reduction and an increase of the parts functionality. However, in order to achieve this, new design methods have to be developed to take into account the specificities of these processes, with the Design For Additive Manufacturing (DFAM) concept. In this context, a methodology to obtain a suitable design of parts built through additive manufacturing is proposed; both design requirements and manufacturing constraints are taken into account.

Manufacturability analysis to combine additive and subtractive processes

Purpose – The purpose of this paper is to propose a methodology to estimate manufacturing complexity for both machining and layered manufacturing. The goal is to take into account manufacturing constraints at design stage in order to realize tools (dies and molds) by a combination of a subtractive process (high‐speed machining) and an additive process (selective laser sintering).Design/methodology/approach – Manufacturability indexes are defined and calculated from the tool computer‐aided design (CAD) model, according to geometric, material and specification information. The indexes are divided into two categories: global and local. For local indexes, a decomposition of the tool CAD model is used, based on an octree decomposition algorithm and a map of manufacturing complexity is obtained.Findings – The manufacturability indexes values provide a well‐detailed view of which areas of the tool may advantageously be machined or manufactured by an additive process.Originality/value – Nowadays, layered manufact...

Environmental Impact Assessment Studies in Additive Manufacturing

This chapter focuses on the environmental studies in additive manufacturing. For a cleaner production, environmental impacts that occur during the manufacturing phase should be assessed with accuracy. First, the literature on all the studies led to the characterisation of the environmental impact of additive manufacturing processes. The studies on electric energy consumption of these processes are analysed here, and then some studies taking into account raw material and all the flows through the process are detailed. Secondly, a new methodology in order to evaluate, with accuracy, the environmental impact of a part from its CAD model is presented. In this methodology, the work is not focused only on electrical consumption but also on fluids and material consumption which also contribute to the environmental impact. In addition, the inputs of this methodology correspond to the set part process, which allows taking into account different manufacturing strategies and their influences on the global environmental impact. The methodology developed is based on both analytic models (validated by experiments) and experimental models. And finally, an industrial example shows that for some manufacturing strategies, the environmental impact due to electrical consumption is not the predominant one. In this case study, material consumption has an important impact and has to be taken into consideration for a complete environmental impact assessment.

Environmental performance modelling for additive manufacturing processes

Sustainability means considering economic, social and environmental aspects. In the mechanical product design field, sustainability means thinking about eco-design and life cycle analysis, when the whole life cycle of the product (from raw material extraction to end of life) is concerned with environmental impacts. Nowadays, most of the manufacturing methods are driven only by money, and the environmental and social aspects are not taken into account. The goal of this paper is to propose an environmental assessment methodology of the manufacturing processes. In this methodology, all flows consumed and produced (material, fluids, electricity) are considered. A predictive model of flow consumption is defined from the CAD model of the product and the manufacturing program. The aim is to be able to minimize the environmental impacts of the manufacturing during the design stage. In this paper, the focus is put on additive manufacturing.