What's the news?
Audi has revealed some of the secrets of the structure of its next A8 model. A combination of four materials is employed to deliver 'extraordinary' torsional rigidity with low weight. Vehicle dynamics, refinement and occupant safety should all benefit from the strength and stiffness of the latest Audi Space Frame.
Since 1994 more than one million vehicles have been built using the company's lightweight technology. The principal employed by Audi is 'the right material in the right place and in the right amount', which means a combination of aluminium, steel, magnesium and carbon fibre reinforced polymer (CFRP).
Aluminium components account for 58 percent of the body, with a combination of cast, extruded and sheet metal components. For the occupant cell and lower front bulkhead Audi has employed hot-formed, high strength steel components. The rear bulkhead is CFRP and contributes 33 percent to the vehicle's torsional rigidity. New processes have been developed for the rear bulkhead to simplify the composite manufacturing process. Completing the materials package is a magnesium strut brace that links the suspension towers to the front bulkhead.
Joining the various materials together involves a number of techniques. A process called roller hemming is used where the aluminium side wall frame meets the steel B-pillar, roof line and sills; this allows larger door openings and thinner A-pillars. Other components are joined by remote laser welding; precise control of the beam reduces the risk of cracking while the feed rate and low energy usage have cut CO2 emissions for this stage of production by one fourth.
Anything else?
The Neckarsulm factory where the Audi A8 is built has been overhauled for the new flagship model. A total of 14,400 metric tonnes of steel was used to construct the 41-metre high body shop; twice as much steel as it took to build the Eifel Tower.