Aluminium Car Front Section Reduces Weight and Emissions

The study analyses the application of aluminium for the structural components of the front section of a state-of-the-art C-class vehicle. Numerical simulation indicates a weight reduction potential of 35% considering the exact design space limitations of the reference vehicle. In a Progressive approach, the design space was expanded as far as possible with respect to the major package components of the reference vehicle to allow more design freedom and encourage innovative ideas. In this case, a weight reduction potential of 41% was achieved, with a significant increase in stiffness plus improved energy absorption in case of a crash. Furthermore, keeping power-to-weight ratio of a car constant, such weight reductions also allow for downsizing of other components leading to secondary weight savings.

The introduction of an aluminium front section in 5 million C-Class cars and a weight reduction according to the Progressive approach plus secondary weight reductions will save 2.2 million tonnes of CO2 over the lifespan of the vehicles, equivalent to saving 770 million litres of fuel3.

Looking at CO2 emissions of a car, the Progressive approach that uses 21.54 kg of aluminium reduces CO2 exhausts by 1.9 grams per kilometre4.

With rising fuel costs and vehicle weights, the use of lightweight materials for automotive engineering is a much-discussed approach for improving vehicle economy. However, lightweight metals have hardly been used for load bearing structures of compact and middle class car bodies. This is despite the fact that fuel economy is often a major selling point for this class of vehicle and that the effect of weight reduction on fuel consumption is most significant in 'stop-start' city traffic, where cars of smaller classes are most frequently used.

In this study, both design concepts had to offer at least the same bending and torsion stiffness as well as crash performance as the reference structure. The objective was to achieve a high level of weight reduction under these constraints. The positive results of the aluminium structure with respect to mass reduction and structural performance identify aluminium as an ideal material for structural components of the front sections of C-class passenger cars.

Source: EAA - European Aluminium Association