An environmental life cycle comparison of various sandwich composite panels for railway passenger vehicle applications

This study reports the results of a comparison made using life cycle assessment (LCA) analysis of the environmental impact of nine different sandwich material models (SMs). The objective is to reveal whether the candidate materials considered for a railway passenger vehicle (conventional or high-speed train) are green/environmentally friendly or not. For this aim, life cycle approach enables to take into account the light weighting gain without disregarding the environmental impact of manufacturing process. These SMs are designed as combinations of existing traditional and candidate materials, such as steel, aluminium, carbon/glass fibre–reinforced plastics (CFRP/GFRP), aluminium honeycomb, and polymer foam core. The environmental performance of these nine different models has been calculated via the LCA analysis with CML-IA v.3.0 impact assessment methodology in a SimaPro 8.5.0. The system boundaries in the LCA analysis include “cradle to grave” process of sandwich composite materials in the railway passenger vehicle. The functional unit was selected as “one product of SM” for each configuration; besides, this panel has a lifetime span of 25 years at 400,000 vehicle-km per year in the vehicle operation. The results show that the use-phase, which dominates the environmental impact of the SMs of the railway passenger vehicle car body, is itself largely affected by electricity generation. In particular, the mass reduction in the models also achieved a reduction in environmental impact over its lifetime, mainly owing to decreased energy consumption. Another important finding regarding the manufacture of certain models (such as CFRP and GFRP) for lightweight design, is that assessment, based solely on mass reduction, may not always have better environmental performance or be reliable due to the manufacturing impact.