Additive-Manufactured Reinforcements for Composite-Metal Joints: A Life Cycle Engineering Approach

This study investigates the environmental implications of enhancing composite-metal hybrid joints using penetrative reinforcements fabricated via Additive Manufacturing (AM). Two design scenarios—reinforced and unreinforced—were analyzed through a comparative Life Cycle Assessment (LCA) following ISO 14040:2021 and ISO 14044:2021 standards, using a cradle-to-gate system boundary. A functional unit was established to ensure meaningful comparison in accordance with the standards. Experimental data were used to characterize material performance, while background data were sourced from databases such as Ecoinvent. Results show that AM-based reinforcements improve tensile strength by approximately 80%, allowing a substantial reduction in the bonding area. This structural optimization translates into a lower environmental footprint, particularly in terms of global warming potential. Despite the high energy demands and material specificity of AM processes, the resulting efficiency gains contribute to a more sustainable design. The findings highlight the potential of performance-driven design strategies, enabled by AM, to advance both structural integrity and environmental sustainability in hybrid joint applications.