Comparing the NVH Behaviour of an Innovative Steel-Wood Hybrid Battery Housing Design to an All Aluminium Design

Abstract

The production of Electric Vehicles (EVs) has a significant environmental impact, with up to 50 % of their lifetime greenhouse gas potential attributed to manufacturing processes. The use of sustainable materials in EV design is therefore crucial for reducing their overall carbon footprint. Wood laminates have emerged as a promising alternative due to their renewable nature. Additionally, wood-based materials offer unique damping properties that can contribute to improved Noise, Vibration, and Harshness (NVH) characteristics. Compared to conventional materials such as aluminium, wooden structures exhibit significantly higher damping properties.In this study, the potential of lightweight wood composites, specifically steel-wood hybrid structures, is investigated as a potential composite material for battery housings for electric vehicles. Experiments have been performed in order to determine the modal parameters, such as natural frequencies and damping ratios. These parameters where used to validate a free-free steel-wood hybrid beam simulation model. The numerical model was subsequently used to analyse the effect of the wood–steel adhesive on the natural frequencies and to compare a steel-wood hybrid battery housing to a aluminium based battery housing. The presented results in conjunction with literature data demonstrate that steel-wood hybrid structures can provide attractive stiffness properties at low weights while utilizing the excellent damping properties inherent in plywood. These properties can contribute to an improved noise and vibration behaviour, which could improve passenger comfort while reducing the life cycle greenhouse gas potential of the structural battery pack components by up to 50 %. The utilization of steel-wood hybrid structures within the battery pack of an EV may also contribute to a reduction in vibration-induced cell degradation, attributed to the higher damping characteristics inherent in these composite materials.This research contributes to the field of sustainable EV design by exploring the advantages of wood composites in the context of NVH optimization. The utilization of steel-wood hybrid structures represents a novel approach to exploit the unique properties of both materials, combining stiffness and damping characteristics. This study offers a pathway towards reducing the environmental impact of EV production while improving the NVH performance of electric vehicles, by incorporating sustainable materials like wood laminates into battery pack design.