Abstract
The aviation sector is looking to replace conventional metals for aircraft structures with composite materials due to the latter’s potentially favourable combination of mechanical properties and low weight. However, relatively little is known about the environmental impacts and economic costs associated with composite materials displacing conventional metal in aircraft applications, and the relevant analysis models have not been well established.
An integrated life cycle assessment (LCA) and life cycle costing (LCC) framework is proposed for assessing environmental and cost performances. The framework and relevant analysis models developed provide a systematic assessment of environmental and economic respective aspects associated with a given product or process. A graphical tool was developed to represent an eco-efficiency (EE) comparison based on the integration of the LCA and LCC results, which is a sustainability measure combining environmental and economic performances for comparing the different alternatives to support material selection.
The displacement of a conventional aluminium aircraft door by a composite door on a life cycle basis is presented as an example of the use of this framework. The scenario analysis, sensitivity analysis and Monte Carlo Simulation as support analyses are carried out to address the data uncertainty. The graphical visualisation tool demonstrates the integrated environmental and economic performances of this displacement. The research found that composite aircraft doors could increase both environmental and financial impacts by 77% over conventional doors across the entire life cycle. The study recommended that the composite door would become favoured if a weight reduction of 45% could be achieved for the future composite door after optimisation and continuous improvement. The EE analysis result demonstrated that, among all the composite door scenarios with various composite waste recycling methods, the pyrolysis recycling with equal quality carbon fibre substitution scenario presented the best environmental and economic performances.
This study presents the pioneering application of a comprehensive framework for analysing aircraft components, while also introducing novel cost and environmental impact models. Notably, this research focuses on addressing the end-of-life recycling challenges specific to composites. This study contributes a new database for inventory datasets and demonstrates a potential improvement method for future aircraft door production. The research looks at the whole aircraft supply chain with a holistic view of the materials and processes, providing a better understanding of the trade-offs and achieving sustainable decisions.