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UltraLight Steel Auto Suspensions (ULSAS) Programme Report

Download the UltraLight Steel Auto Suspensions report.

  • Achieve mass savings of up to 34% over current steel design at no additional cost
  • Match the mass of aluminum system, while achieving 30% cost benefit
  • Does not compromise performance
  • Is manufacturable in high volume at no cost penalty

UltraLight Steel Auto Suspensions, lighweight solutionsThe UltraLight Steel Auto Suspension (ULSAS) Programme is a primer on understanding and exploiting the properties of steel as well as a showcase for the best automotive design technology. Lotus Engineering, a world-class consultant in vehicle and chassis engineering, with widely recognized expertise in vehicle dynamics, conducted the study.

The objectives of ULSAS – and in fact of all the steel studies — were to:

Show the potential for optimized, cost-effective, environmentally-friendly and lightweight steel-intensive solutions

Explore and promote the full range of steel product and process technologies

Develop steel-based design concepts that meet or exceed modern standards of performance, safety and efficiency

Assist the automakers with the competitive challenges of reducing mass while satisfying a range of technical, safety, environmental and consumer demands.

The ULSAS project was conducted over a period of two-and-a-half years and was structured in two phases:

  1. The first phase focused on benchmarking vehicles and systems from the world’s major markets, and the selection of aggressive mass, cost and performance targets.
  2. The second phase involved development of a range of specific, generic designs for suspension systems that met or exceeded the targets.

Importantly, from beginning to end, the program was configured as a mainstream product engineering design study for production-feasible, rear suspension assemblies.

The Lotus Unique design makes extensive use of high- and ultra high-strength steel, while simplifying and minimizing the number of components through integration. Part of this is realized through the use of tailored blanks in the fore-aft arm. The design provides packaging advantages, such as providing more luggage space. The study also showed it would be easy to manufacture and assemble.

ULSAS demonstrates that affordable mass savings have been achieved when compared with conventional steel-based designs, and cost savings have been achieved with no mass penalty in comparison to the aluminum-intensive benchmarked system.

The ULSAS systems meet or exceed the benchmark standards in all other key criteria, as well.

In summary:

  • The mass savings achieved by the Twistbeam, Strut and Links, Double Wishbone and Lotus Unique systems
    up to 34 percent lighter than that of the respective benchmarks
  • The slight reduction in mass over the benchmarked aluminum-intensive Multi-Link system, while providing a 30 percent cost reduction.
  • The results are a clear indication of what can be achieved with the latest steels and technologies.

ULSAS consortium members included:

Aceralia Transformados S.A.
Acme Metals Incorporated
AK Steel Corporation
American Iron and Steel Institute
Bethlehem Steel Corporation
BHP Steel – Rod, Bar and Wire Division
Bohler Uddeholm AG
British Steel Engineering Steels
Cockerill Sambre R&D
Dofasco Inc.
Georgsmarienhutte GmbH
Hoogovens Staal B.V.
Ispat Inland Inc.
Ispat Stahlwerk Ruhrort GmbH
Kawasaki Steel Corporation
Kobe Steel, Ltd.
LTV Steel Company
National Steel Corporation
Nippon Steel Corporation
NKK Corporation
Pohang Iron & Steel Co., Ltd.
Rautaruukki Oy
Rouge Steel Company
Stelco Inc.
Sumitomo Metal Industries
The Tata Iron and Steel Co., Ltd.
Thyssen Krupp Stahl AG
U. S. Steel Corporation
USS/Kobe Steel Company
Vallourec Group
Voest-Alpine Stahl Linz GmbH
VSZ Holding A.S. Kosice
WCI Steel Inc.
Weirton Steel Corporation