New Automotive Study Helps Auto Engineers Reduce Vehicle Weight
Greener, Lighter, Safer Steel Vehicles Can Be Achieved Through New Vehicle Noise, Vibration and Harshness Approach
Detroit, 22 April, 2009 – A study commissioned by WorldAutoSteel and presented today at the Society for Automotive Engineers 2009 World Congress shows automotive engineers a new approach to design for noise, vibration and harshness (NVH) called “Hybrid Interior Noise Synthesis (HINS).” The study illustrates how vehicle components can be optimized for NVH performance and weight by applying the new approach and lightweight steel solutions.
“Applying this approach with steel technologies equips automotive engineers with methodology that significantly improves the component design process for fuel efficient vehicles,” said Ed Opbroek, Director, WorldAutoSteel. “Control of the overall vehicle weight is critical.”
The study was presented at SAE by Juliette Florentin of LMS International (www.lmsintl.com), who conducted the study on behalf of WorldAutoSteel, and Toyoki Yamamoto, Nippon Steel (WorldAutoSteel member), who provided steel technical expertise to the project. The new HINS approach was applied to a BMW 1-series firewall with integrated cross beam. This HINS method associates a virtual firewall structure with a test-based body model. The vibro-acoustic model includes the firewall structure, trim elements, full vehicle boundary conditions and an acoustic model of the passenger cabin. It is used for predictions of structure-borne engine noise in the 40 Hz to 400 Hz range.
The short calculation time of this set-up allows a wide range optimization, where multiple design iterations can be completed quickly. A significant number of modifications to the firewall and associated transverse beam were modeled to determine impact on weight and NVH.
“We focused on a firewall, as it is a dominant panel for noise and vibration concerning the structure-borne engine noise,” said Yamamoto. “And we chose the BMW 1-series firewall because it is already a superior design that would be difficult to improve upon, therefore creating a proper challenge for this new approach.”
The results showed that both weight and NVH could be reduced through design changes and use of steel processing technologies, such as tailor-welded blanks (TWB). The TWB allows for greater thicknesses in weaker areas rather than a fully over-designed beam. Bead designs were implemented on the firewall that showed potential to bypass expensive damping sheet treatments, commonly applied to reduce the amplitude of vibrations. The noise contribution of the firewall was improved by 0.9 dB, its mass reduced by 5.1 percent, and the structure maintained the same level of crashworthiness.
“This is a good result considering that we only had access to the firewall and were testing a front-end design that is already quite advanced,” Florentin noted. “If this approach was applied early on in the design process, we may be able to achieve additional weight reduction.”
The study overall demonstrated that complex steel designs are successful at achieving better noise performance while improving mass, yet not compromising crashworthiness. For more spectacular improvements, the study recommends that NVH be addressed earlier in the design process.
For more information, please contact:
For Europe & Asia Pacific:
Cees Ten Broek, Director Communications, WorldAutoSteel
T: +32 2 702 89 33 begin_of_the_skype_highlighting +32 2 702 89 33 end_of_the_skype_highlighting
M: +31 6 53 33 86 23 begin_of_the_skype_highlighting +31 6 53 33 86 23 end_of_the_skype_highlighting
For the Americas:
Kate Hickey, Communications Consultant, WorldAutoSteel
M: +1 734 905 0062 begin_of_the_skype_highlighting +1 734 905 0062 end_of_the_skype_highlighting
About WorldAutoSteel
WorldAutoSteel, the automotive group of the World Steel Association (www.worldsteel.org), continually explores steel innovation that demonstrates and communicates the value of steel in automobiles to industry and society. Its member companies from around the world pool global resources within and beyond the steel industry to deliver vital research that is central to effective steel automobile applications. WorldAutoSteel continues to lead the materials revolution through projects like the Future Steel Vehicle (FSV) program, a multi annual program that will deliver auto body concepts that address alternative powertrains, such as advanced hybrid, electric, and fuel cell systems.
The FSV program is the fifth in a series of auto steel research projects, following on the heels of the UltraLight Steel family, which revolutionized the kinds of steels normally applied to auto bodies, as well as demonstrated innovative steel vehicle designs. The application of these research findings is seen globally in many vehicles on the road today. These are ULSAB, ULSAC, ULSAS, and ULSAB-AVC (Advanced Vehicle Concepts). The FSV program is expected to stimulate the same developments in upcoming alternative vehicles.
Members of WorldAutoSteel are:
- Arcelor Mittal - Luxembourg
- Baoshan Iron & Steel Co. Ltd. - China
- China Steel Corporation - Taiwan, China
- Hyundai-Steel Company - South Korea
- JFE Steel Corporation - Japan
- Kobe Steel, Ltd. - Japan
- Nippon Steel Corporation - Japan
- Nucor Corporation - USA
- POSCO - South Korea
- Severstal - Russia/USA
- Sumitomo Metal Industries, Ltd. - Japan
- Tata Steel & Corus - India, UK, Netherlands
- ThyssenKrupp Steel Europe AG - Germany
- United States Steel Corporation - USA
- Usinas Siderúrgicas de Minas Gerais S.A. - Brazil
- voestalpine Stahl GmbH - Austria
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