Understanding the sustainability potential of part consolidation design supported by additive manufacturing

The environmental performance of additive manufacturing (AM) processes and the produced parts has gained increasing interest. Various assessment models have been developed based on the general life cycle assessment (LCA) framework, although different in goals and boundaries, the inputs for these models are always a single part (or a batch of same parts). In contrast, the present research provides a new perspective towards the selection of a more sustainable assembly design. A comparative LCA model is built to investigate the environmental performance difference of two design approaches: assembly design (AD) made via conventional manufacturing (CM) plus assembly operations and part consolidation (PC) made via AM plus machining. The effects of weight reduction, prolonged life expectancy, and improved functional performance (e.g. fuel efficiency) attainable in the PC routine and the advantages of replaceable subcomponents in the AD routine are studied in a throttle pedal assembly example throughout the lifespan of the vehicle. The results reveal that the PC routine can be more environmental friendly than the AD counterpart when the lifespan can be improved by over 200% or the weight savings are more than 30%. The role of functional performance improvement on affecting sustainability may depend on the part/vehicle ratio and vehicle types. This article extends the literature on sustainable assembly design and the proposed LCA model provides a way of identifying the profitable margins of PC in the early design stage. (C) 2019 Elsevier Ltd. All rights reserved.