Sustainability assessment of bulletproof materials used for vehicle armouring

Abstract

The increasing demand for lightweight, highly protective armoured vehicles has shifted material selection from ballistic performance alone to comprehensive sustainability considerations. While traditional homogeneous armour steels provide excellent durability, mature manufacturing technologies, and high recyclability, their high density significantly increases vehicle mass, leading to greater fuel consumption and greenhouse-gas emissions throughout the operational life cycle. Conversely, advanced composite armour systems offer superior protection-to-weight ratios but are associated with energy-intensive manufacturing processes and limited end-of-life recycling options. This study presents a comparative life-cycle sustainability assessment of steel- and composite-based vehicle armouring materials using a cradle-to-grave engineering framework. In addition to evaluating ballistic performance and material characteristics, the proposed methodology integrates manufacturing energy demand, operational fuel consumption, greenhouse-gas emissions, recyclability, and economic considerations. A simplified quantitative model is introduced to describe the relationship between armour mass, vehicle fuel consumption, and operational CO₂ emissions, while a sensitivity analysis is performed for representative armoured vehicle configurations. Furthermore, a multi-criteria decision analysis (MCDA) framework is proposed to support engineering decision-making by simultaneously considering ballistic efficiency, environmental impact, operational performance, recyclability, and cost. The results demonstrate that although homogeneous steel remains advantageous in terms of manufacturing maturity and circularity, lightweight composite materials substantially reduce operational environmental impacts owing to lower vehicle mass. The analysis further indicates that hybrid modular armour systems provide the most balanced engineering solution by combining the recyclability of steel with the weight-saving benefits of advanced composites. The proposed assessment framework extends conventional material comparisons by integrating engineering, environmental, and economic perspectives into a unified sustainability evaluation methodology, thereby providing practical guidance for the future development of armoured vehicle protection systems.