2016 Enlighten Award in Review – No. 20: Cadillac CT6

28th July 2017 by Richard Yen

Before we announce the winners for this year’s Altair Enlighten Award on Monday, we’ve just got time to finish off our look back at last year’s nominations. Today it’s the turn of our overall winner for the full vehicle category, the Cadillac CT6 and its ‘Omega’ architecture.

Computer aided engineering (CAE) tools and methods were developed and used to create an efficient, lightweight, high-performance, mixed-material vehicle structure.  These tools, which included immersive lattice topology optimization, mixed material selection optimization, and multi-disciplinary loadcase optimization, were used, along with expert interpretation of the results, to lead the design development of the architecture and lead vehicle structure.

Multi-disciplinary optimization (MDO) tools and techniques were applied to material selection for the BIW structure.  This enabled a ‘right material in the right place’ approach to minimize structural mass while achieving high levels of performance.  Unique and novel joining methodologies were developed in parallel to enable the mixed-material body construction.  Manufacturing considerations were integral to making design and material choices. Extensive design studies to determine optimum configurations for optimum performance were conducted including, as an example, vehicle level trade matrix studies for optimum (cost, mass, and package) material usage for NVH performance.

To achieve the mixed material body, GM needed to overcome the challenges of joining dissimilar materials in a high volume production vehicle. This included the design and execution of large a single piece body side outer in aluminum while managing differential thermal expansion of mixed material body structure – leading to a 2 test weight class reduction in vehicle mass compared to primary competitive vehicle while maintaining a larger vehicle size and driver/passenger space. The team at GM eased the development process through the knowledge gained during the development of other mixed material vehicles in its product range.

The CT6 Omega Architecture achieved a 71.5 kg body mass savings over an equivalent sized ‘traditional’ BFI construction but what really impressed our judges was the holistic approach to weight saving seen throughout the vehicle. A variety of complementary lightweight materials were used throughout the vehicle, supported by a massive deployment of design optimization technologies and techniques.

Following the award, GM kindly did an interview with us, giving some insight into the development of the vehicle. I would encourage you to spend a few minutes to watch the video and see how they approached the overall development processes. And of course, don’t forget to join us on Monday to see who will take home this year’s Enlighten Awards.