Contribution of Body Lightweight Design to the Environmental Impact of Electric Vehicles

Abstract

In today's society the continuously increasing consumption of raw materials and the associated impacts on the ecosystem tend to be a frequently discussed topic. Especially automobile companies are faced to develop new driving concepts due to the emerging energy turnaround. Usually the components of the conventional drive are replaced by an electric engine including the required energy storage. Without structural changes regarding the chassis this procedure causes an increase in the vehicle ́s weight (Conversion Design). Therefore a new approach is to integrate the battery as a load-bearing member in the vehicle structure and additionally use a weight-optimized multi-material design of the body (Purpose Design). By savings of 25% of the weight of a compact-class vehicle body, a resource-saving and energy-efficient design of the entire vehicle can be achieved. Certainly the innovative multi-material construction contributes significantly to reduce the total energy consumption of the vehicle during the use phase. Based on a Lifecycle-Assessment (LCA) the environmental sustainability of the Purpose Design will be evaluated and compared to the approach of the Conversion Design. In addition to the weight savings of the multi-material body secondary weight reductions regarding the energy storage will be taken into account. The aim is to assess the ecological advantages of the lightweight solution throughout the entire product life cycle comprising the extraction of raw materials, production of the components, use of the product and end of life including the recycling of components. However, these investigations will be carried out for the modified chassis and the lightweight constructed multi-material body. Hence, the processes of the individual life cycle phases will be collected, inventorial analysis carried out and impact assessments performed. According to the LCA it will be tested, if the additional expenses in raw material extraction, production and recycling of the lightweight body justify the expected ecological advantage in the use phase. A final overall analysis will provide information on the actual efficiency and sustainability of the Purpose Design. Due to the parallel creation of the LCA data during the development process the LCA results furthermore serve to detect and monitor significant shortcomings on component and assembly level.