Audi is the winner of the EuroCarBody AWARD from the Automotive Circle International for the innovative body concept of the Audi TT. The sports coupé beat off 13 competitors from around the world to take the award. The Ingolstadt brand developed its groundbreaking Audi Space Frame (ASF) technology in the early 1990s for the Audi A8. The body of the new TT represents the first application of the ASF with a hybrid construction, featuring an elaborate composition of aluminium and steel.

This prize pays tribute to the work of Audi developers who have again presented impressive proof, in the form of the new TT body, of how Audi leads the way in this field. In ASF technology, the body''s supporting structure is made of extruded aluminium sections and die-castings, with the aluminium sheet panels forming a positive connection and performing a load-bearing role within this structure. The components of the ASF space frame vary in shape and cross-section depending on their function – like the bones of the human skeleton, they are made to fulfil their task as well as possible, while having the minimum possible weight. 

In the new TT, Audi has further developed ASF technology, and added high-strength steel to the material mix. Aluminium accounts for 69 percent of the total body weight. Steel components are used at the rear of the floor assembly. The doors and boot lid are also made of steel. This provides an optimum distribution of axle loads, making for superior handling.

The TT body-in-white weighs 206 kg, of which 140 kg is aluminium and 66 kg is steel; as an all-steel construction it would be 48 percent heavier. The aluminium components of the ASF comprise 63 kg of sheet, 45 kg of castings and 32 kg of extruded sections. 

The new form of ASF developed for the Audi TT has qualities that are perfect for a sports car. The static torsional stiffness of the Coupé is roughly 50 percent higher that that of its predecessor; on the Roadster the increase is an incredible 128 percent.

Extremely resilient cast components have been used in areas subjected to high local forces and where multifunctionality is required. A prime example is the A-post node – this is a high-tech component that connects the longitudinal member, sill, A-post and windscreen cross-member. 

Audi is profiting from its vastly superior wealth of experience when it comes to joining together aluminium and steel components. Joining is performed in a variety of ways – punch-riveting, clinching and bonding. A fourth joining technology has now been added to the list: self-tapping screws, inserted by robots, melt the surface of the component as a result of the friction they cause, thus penetrating fully into the material, forming a positive connection with it. Another innovative concept used on the new TT is the aluminium zero joint that is produced between the roof and the side section during laser-welding.

This technique also enhances ride comfort by reducing vibration. It took only a few simulation cycles on the computer to arrive at a structure that suppresses incipient vibration and avoids transmission paths.

In terms of crash safety, too, the new TT is utterly uncompromising. This is the second time that Audi has received the coveted award. In 2003 Europe''s most prestigious innovation prize for body construction went to the Audi A8. The A8 also has an ASF body.