Advanced high-strength steels enable vehicle structures to be safe and mass efficient
DETROIT, May 1 /PRNewswire/ -- American Iron and Steel Institute's Steel Market Development Institute (SMDI) announced today that it is supporting automakers in their efforts to meet new roof-crush standards implemented by the National Highway Traffic and Safety Administration (NHTSA).
"The advanced high-strength steels (AHSS) developed by North American steelmakers have provided automakers with cost-effective, lightweight solutions that enable OEMs to achieve the most crashworthy vehicles ever to be deployed on American highways," Ron Krupitzer, vice president of automotive applications for AISI's SMDI, said. "North American steel companies have been working with automakers to develop advanced steel technologies, designs and processes to improve vehicle structures, including roof architectures, to meet safety, weight and cost-saving goals. These solutions are being deployed today on the best performers in vehicle crash safety."
NHTSA issued a final rule requiring automakers to manufacture vehicle roofs that withstand three times the vehicle's weight on both sides of a roof - up from 1.5 times. The mandate, which is part of an initiative to reduce rollover fatalities and injuries, applies to vehicles weighing up to 6,000 pounds.
According to Krupitzer, the Auto/Steel Partnership (A/SP) - a unique consortium consisting of Chrysler, Ford Motor Co., General Motors Corp. and the AISI SMDI Automotive Applications Council investor companies - have been working on mass-efficient designs with AHSS for years to help automakers meet increased safety performance during all types of crashes.
The Mass Efficient Architecture for Roof Strength (MEARS) program - an initiative to develop a roof architecture using AHSS materials - investigated the impact of three different grades of steel and architectural elements to hold a load three times (twice the previous NHTSA standard) the vehicle's maximum weight, while achieving less than 4.5 inches of roof deflection. The initial phase examined the roof strength of three different vehicle concepts, while keeping mass, cost, manufacturability and reparability in mind. The final results achieved increased performance and load requirements and reduced mass by 4.4 kg.
"We worked with engineers at Ford to develop a structure for the Ford F-150 Super Cab that combines advanced high-strength steel and tube hydroforming, which addressed the challenge of meeting fuel economy standards and increased performance," Roger Heimbuch, executive director of the A/SP, said. "The result was a body structure that meets new roof strength NHTSA standards, while reducing vehicle mass."
AISI and the A/SP have also addressed roof strength through the Future Generation Passenger Compartment Validation program using a 2008 production vehicle as the program baseline. Heimbuch said, "The project achieved roof strength of 3.7 times the vehicle weight, while reducing mass by 17 percent. The results of these studies and other steel solutions to address the new roof strength regulations will be presented at this year's Great Designs in Steel seminar on May 13 in Livonia, Mich."
The Automotive Applications Council is a part of AISI's Steel Market Development Institute. The council focuses on advancing the use of steel in the highly competitive automotive market. For more news or information, visit www.autosteel.org.
Automotive Applications Council members are:
-- ArcelorMittal Dofasco
-- ArcelorMittal USA
-- Nucor Corporation
-- Severstal North America Inc.
-- United States Steel Corporation
SOURCE American Iron and Steel Institute
