Reducing vehicle weight was and is a serious challenge among automakers to reduce their product’s environmental footprint by reducing their energy consumption. Vehicle weight reduction–that is, making the vehicle more structurally efficient—is one critical factor for meeting environmental performance requirements. Additionally, automakers have the extra challenge to achieve this structurally efficient weight reduction while also improving safety and maintaining affordability—requirements that may be in direct opposition to each other. In many cases, automakers began to look at alternative, low-density materials instead of steel to meet the challenges they faced.
In 1995, a unique consortium of steel companies came together pooling funds and resources to provide a demonstration of the latest in advanced steels and steel technologies, giving automakers practical examples of how this new generation of steels could not only meet these challenges, but also do it affordably. So important was this initiative that on a global basis, it grew to a research and development effort involving thirty-five steel manufacturers, representing twenty-two countries, in an independent international UltraLight Steel Auto Body (ULSAB) Consortium. This project initiative ultimately built demonstration hardware that achieved an unprecedented 25 percent reduction of vehicle body structure weight compared to conventional steel body structures of that time.
ULSAB received wide acceptance by the automotive industry. So much so that it was followed by
three other steel consortia projects in short succession covering closures (UltraLight Steel Auto Closures—ULSAC), suspensions (UltraLight Steel Auto Suspensions—ULSAS) and full vehicle design (UltraLight Steel Auto Body – Advanced Vehicle Concepts—ULSAB-AVC). Each one used a larger percentage of a new generation of steel, Advanced High-Strength Steels (AHSS) along with advanced fabrication technologies such as tailored blanks, hydroformed tubes and continuous laser welding, achieving structural efficiency never before seen in automotive structures.
All of the project findings, though patentable, are made available in the public domain, free of charge at the worldautosteel.org website. The results were communicated globally by the consortia members and every effort was made to assist automakers in replicating these
innovative AHSS applications in their vehicles to achieve vehicle weight reduction/fuel efficiency goals.
Since the last of the UltraLight projects was launched in 2002, public policy emphasis on reducing vehicle carbon footprint has grown even stronger. It is the topic of emerging regulations in nearly every region of the world, adding new urgency to emissions reduction strategies. Most of these regulations are focused on reducing tailpipe emissions—that is only the “use” phase of a vehicle’s total life cycle.
Major elements affecting vehicle tailpipe emissions are (1) powertrain efficiency, (2) aerodynamics, (3) rolling resistance, and (4) vehicle weight. Material choices concerning steel and competing materials most directly influence vehicle weight and its structural efficiency.
Steel’s potential was sometimes overlooked when the focus is exclusively on the tailpipe, use phase,
of the vehicle life cycle. Two issues must be explored to address this. First, automotive structural designs must maximize the application of Advanced High Strength Steel and design optimization techniques instead of previous conventional steel designs. The second issue is that material choices must be considered on a total life cycle basis. The use of low-density, greenhouse gas (GHG)-intensive materials such as aluminium, magnesium, or composites may provide lighter weight components that improve fuel economy and reduce tailpipe emissions. However, this may have the unintended consequence of increasing GHG emissions during the vehicle’s total life cycle because greenhouse gases (GHG) emitted in order to produce functionally equivalent automotive components from different materials are much greater than for Advanced High Strength Steels.
The following figure illustrates the Total Life Cycle concept for steel (also similar for other materials):
It should be noted that fuel economy or tailpipe emission regulations that consider only the vehicle use phase can encourage use of low-density, GHG-intensive materials with the unintended consequence of embedded materials production emissions that are greater than the use phase emission reduction.
Consequently, at the December 2007 United Nations Framework Convention on Climate Change conference in Bali, the consortia of steel manufacturers, now operating together as WorldAutoSteel, announced the commencement of the FutureSteelVehicle (FSV) program. The program’s objectives were to deliver auto body concepts that address radically different structures for advanced powertrains such as advanced hybrid, electric, and fuel cell systems, demonstrating safe, lightweight steel structures for future vehicles that reduce GHG emissions over the total life cycle.
WorldAutoSteel announced FSV’s final results in May 2011. Life Cycle Assessment (LCA) was included as an integrated part of
FSV’s design and engineering, guiding decisions throughout the process. Because of this FSV’s results vividly demonstrate that the coupling of a lightweight AHSS body structure combined with a battery electric powertrain achieves a fifty to seventy percent reduction in total vehicle life cycle emissions (depending on the energy source) compared to comparably-sized vehicles with conventional internal combustion gasoline engines.
FSV demonstrates state-of-the-future design optimization methodology combined with an expanded portfolio of High-Strength (HSS) and Advanced High-Strength (AHSS) steels and an array of steel technologies to achieve 35 to 39 percent vehicle body
structure mass savings in a Battery Electric Vehicle. In addition to reducing life cycle emissions, FSV’s body structures enable five-star crash safety performance and maintain steel’s affordable costs.
The UltraLight series of steel research projects revolutionized the kinds of steels normally applied to vehicle architectures and demonstrated cutting edge steel vehicle design. AHSS applications can be found in nearly every vehicle on the road today around the world.
FSV is stimulating similar developments in upcoming advanced powertrain vehicles. FSV has already received wide acclaim in the automotive industry and has provided viable, affordable solutions that achieve weight savings on par with those claimed by competing materials.
WorldAutoSteel continues as an unprecedented consortium in world industrial history, bringing competing steel manufacturers together in a close-knit working environment to achieve common precompetitive goals—providing solid technical data, practical demonstrations, and public advocacy where needed, accomplishing much more together than could be achieved by and individual company efforts.
The story of how this unique consortium of steel companies was created and functioned so successfully is described in a book written by former Director Ed Opbroek, entitled UltraLight Steel: A Global Consortium Changes the Future of Automotive Steel. This article has been excerpted from Mr. Opbroek’s book by permission.