ALLIANCE – Sustainable, cost-efficient lightweight design for mass production

Lightweight construction is an important method of increasing the efficiency of vehicles. It is important to evaluate the added value generated by the use of innovative materials and manufacturing technologies in a holistic way. In addition to considering the achievable lightweight potential, this also includes the analysis of the environmental impacts arising over all life cycle phases (production, use and recycling) and the quantification of the additional lightweight costs (€/kg) associated with these technologies. This holistic approach is part of the "Life Cycle Engineering" (LCE) theme.

As part of the EU-funded "ALLIANCE" project, automobile manufacturers, materials suppliers and research institutes have joined forces to address the issue of cost-efficient and sustainable lightweight design and to promote the use of innovative technologies in large-scale production.

Within the project, material suppliers and research institutions are working closely with automotive manufacturers to further develop the technology readiness level (TRL) of their materials and manufacturing processes from the first laboratory tests (TRL4) to the use in physical prototypes (TRL6). On the materials side, the focus is on high-strength steel and aluminium alloys, fibre-reinforced plastics and metal-plastic composites. From the production point of view, the main focus is on forming processes for metallic materials, manufacturing processes for metal-plastic composites and thermoplastic composites, as well as joining technologies for multi-material constructions. The knowledge gained with regard to the new technologies will then be implemented as prototypes in demonstrator components. Vehicle manufacturers have identified components from current production vehicles in order to implement the corresponding lightweight construction technologies. These include doors and closures, floor and carrier structures, as well as energy-absorbing structural components. The objective of the lightweight construction efforts is to achieve a reduction in energy consumption of 10 % in the use phase by means of an average weight saving of 25 % at a quantity of 100,000 units per year and at additional costs of a maximum of 3 €/kg weight saving. At the same time, emissions, measured as global warming potential, are to be reduced by 6% over the entire life cycle.

fka and the Institute for Automotive Engineering (ika) of RWTH Aachen University have jointly developed an evaluation methodology to quantify the potential of these and other lightweight construction technologies at the overall vehicle level. The results of the prototypically implemented lightweight construction technologies will be transferred from the prototypes to the ALLIANCE overall vehicle by means of scaling and transfer methods and evaluated with regard to the project objectives. The virtual vehicle model currently comprises two powertrain configurations (internal combustion engine and battery electric)

With the help of the method and on the basis of the implemented technology database, material and structural concepts tailored to the target values of a vehicle project can be compared, selected and optimised in the future.