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The 2016 Cadillac CT6 sedan, Altair’s Full-Vehicle Enlighten Awards winner for 2016, is described as being at the vanguard of current multi-material lightweighting strategy for entire vehicle architectures.

Altair names 2016’s lightweight standouts

The auto industry’s annual award program devoted exclusively to vehicle mass-reduction innovations recently named General Motors' Cadillac CT6 and ContiTech’s polyamide crossbeam as winners of its 2016 Full-Vehicle and Module categories, respectively.

Now in its fourth year, the Enlighten Awards are sponsored and organized by Altair Engineering, in collaboration with the Center for Automotive Research. The awards cover multiple categories and are open to OEMs, systems/parts suppliers and materials suppliers from all auto industry segments. The winners were announced Aug. 1 during the 2016 Management Briefing Seminars at Traverse City, MI.

The CT6 prevailed over seven Full-Vehicle finalists because of its outstanding strategic approach to weight reduction, the panel of eight judges concluded. The all-new CT6’s acclaimed on-road dynamics and vault-quiet interior are achieved in part by extensive simulation work to create a multi-material variant of GM’s global Omega II vehicle architecture. The Omega structure is aluminum-intensive, but for the CT6 it uses 13 different materials customized for each area of the car.

In total, about 64% of the CT6 body structure is aluminum, including all exterior panels. Various grades of steel are employed in key structural areas. GM engineers said the base CT6 is 90 kg (198 lbs) lighter than a predominantly steel counterpart (, “and it’s lighter than an aluminum design would be as well,” Travis Hester, Executive Chief Engineer, told Automotive Engineering. Base curb weight is less than 3700 lb (1678 kg), about equal to that of the (midsize) Cadillac CTS, which is 8 in (203 mm) shorter overall.

Software simulations used in developing the CT6 body-in-white are credited for optimizing the full-size car’s weight. The lower cabin structure, for example, uses steel close-out panels. The simulation analyses showed that steel alone would be lighter than aluminum without requiring the NVH abatement measures necessary for an aluminum-intensive design to meet GM’s cabin-noise requirements.

GM’s mixed-material strategy also enabled Hester’s development team to achieve a 20% reduction in body-structure bill of materials—the CT6 has 412 parts total—versus a normal steel body, he said.

ContiTech crossbeam wins Module category

Winner of the 2016 Enlighten Awards’ Module category, beating out 13 other finalists, is ContiTech’s polyamide transmission crossbeam featured on the latest Mercedes-Benz S-Class as well as other Mercedes models fitted with all-wheel drive. Incorporating BASF’s Ultramid fiberglass-reinforced polyamide, the composite crossbeam is claimed to be about 25% lighter compared with an aluminum diecast counterpart.

“The new rear-axle transmission crossbeam is a milestone in the use of polyamides in the chassis and has the potential to set a new trend in the automotive industry,” said Kai Fruhaf, head of the ContiTech vibration-control business unit. “Polyamide is increasingly replacing metal. And we’re right there in the forefront of helping manufacturers gradually replace metal with high-performance plastics.”


Company engineers claim that polyamide, unlike aluminum, can be formed at lower temperatures and offers various recycling options. Fruhaf’s team has been using BASF Ultramid since 2006 for bearings and also uses the material in other automotive applications that include millions of torque-reaction mounts. Interestingly, the Cadillac CT6 also uses a polyamide material for its suspension strut mounts.

Dave Mason, Altair’s Regional Managing Director, Automotive, provided context for this year’s Enlighten Awards program: “If you review all the vehicle designs in 2016, there are already great examples of almost every material/manufacturing option on the road today. This is the good news in terms of meeting the new CAFE standards, as the automotive OEMs have been very aggressive over the last two design cycles applying these new materials selectively so that they could learn and perfect their design, manufacturing and assembly processes."

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