Why Is a Vehicle Introduced in 2011 Relevant Right Now?
Back in 2011, WorldAutoSteel, a global organization of steel companies, released what was called the "Future Steel Vehicle." This was a concept that was meant to show the advantages that steel could provide to OEMs. It wasn't an exercise that essentially came out with a cool-looking vehicle that could be pointed to with a "See what you can do with steel!" but, rather, a three-year engineering execution that looked at body structure, front and rear suspension, closure panels, drive train, brakes, bumpers and the other elements that make up a car, not only coming up with the functional designs, but determining the most appropriate materials for each, as well as the manufacturing processes that would be necessary to most efficiently produce them. Oh, and they also looked at the existing and potential options that may not have included steel. And surprisingly, they looked beyond just a traditional internal combustion powertrain to things like battery electric vehicles.
When all of the work was done they came up with a design that had a 35 percent mass reduction compared to an existing, comparable, car (yes, they did a car, not a crossover, so perhaps they were ahead of the curve vis-a-vis looking at an EV, but not as regards the body type) and it used 97 percent high strength and advanced high strength steel, of which about 50 percent was ultra-high strength steel. Notably, it was calculated (based on the then-existing metrics) that it would have 5-star safety, and there would be no cost penalty.
While there was no FSV built, Dr. Jody N. Hall, vice president of the automotive market for the American Iron and Steel Institute Steel Market Development Institute (smdisteel.org), responsible for the Automotive Applications Council and coordinator of the Auto/Steel Partnership (all of which is to say that she spends a lot of time in Detroit dealing with, well, steel), says that right after the FSV (and its associated documentation) was released, OEMs started deploying the materials and processes that it used. (She knows first-hand because before joining AISI in 2014 she'd been a technical integration engineer-steel applications at General Motors.) "All of the companies took bits and pieces. And as they started feeling confident about the new grades or the new manufacturing processes, they began to use more." Although there was a material/manufacturing aspect to the FSV, she acknowledges, "You can have one without the other"--as in using a particular material without the manufacturing process used in the FSV--"but when you combine them you optimize the performance and the mass of the components."
So what's the relevance of the FSV of 2011 to vehicles being engineered today?
It goes to two things that Hall mentions: the performance and the mass. And those two things go to two abiding issues: safety and cost.
To the point of safety, which Hall says is the top criteria when it comes to consumers and vehicles (75 percent), she notes, "It is not the material that is safe but how the engineers can design with the material. With steel it is far more efficient and cost-effective to design with steel for safety. The efficiency comes because it is so high in strength so you don't have to have massive geometries for performance." For example, she cites the A pillars on some vehicles that are made from aluminum, which have a considerably larger section than comparable ones made with steel. A-pillars contribute to vehicles being able to meet rollover requirements. But if those A-pillars are too large, then they attenuate the ability of drivers to see out of the vehicle, which can be unsafe not only to people in the cabin, but to pedestrians and others outside of the vehicle.
Hall says that there was a proliferation of advanced high strength steels developed in the 1990s to help OEMs address safety-related demands. "If someone tried to do it with the mild and high-strength steels that were available at that time, they'd be adding quite a bit of mass to the vehicle, which they couldn't do." While this wasn't a matter of increasing CAFE numbers, CAFE was still an issue, and during that period of time there was an increase in the number of electrical and electronic devices--ranging from motors for powered seats and liftgates to infotainment systems--that was adding mass. "They had to meet collision standards with the same overall mass, so we developed advanced high-strength steels."
Then there is the cost she mentioned.
She posits a structure that is advanced high-strength steel intensive. It weighs 1,197 kg and the vehicle that is built with it, based on current CAFE standards, achieves 31.4 mpg. It would cost the OEM an additional $400 compared to the manufacturing cost of a standard vehicle produced today.
If that same structure is made with an AHSS body-in-white and aluminum closure and chassis components the weight goes down to 1,149 kg and the miles per gallon increase to 31.6. There is, however, an additional cost for that 0.2 mpg increase: $210 on top of the $400.
An aluminum-intensive vehicle reduces the mass by 89 kg and boosts the miles per gallon to 31.8, but the cost premium over the AHSS-intensive structure, Hall says, is $820.
Finally, were the structure to be made with a mixed material array of aluminum, magnesium and carbon fiber, the mass would go down to 1,060 kg, a reduction of 137 kg from the AHSS-intensive vehicle. This would result in 32 mpg, but that would come at an additional cost of $2,680 compared to the AHSS vehicle.
That is to gain 0.6 mpg. So let's say that the vehicle drives 12,000 miles. With a fuel efficiency of 32 mpg, that means it will require 375 gallons of gas. Let's compare that with the AHSS-intensive vehicle that gets 31.4 mpg and travels the same distance. It would require 382 gallons of gas, or about seven more gallons than the vehicle that has that $2,680 premium.
All of which is another way of considering efficiency. Which is still an issue, whether it goes to meeting global fuel efficiency/emissions standards or a price that consumers are willing to pay.
BY GARY S. VASILASH, Editor-In-Chief
The materials and processes that were used to create the structure of the Future Steel Vehicle. Let's face it: there weren't a whole lot of hot-stamped, laser-tailored blanks being used in 2011. And how many people were even aware of TRIP (transformation induced plasticity) steels? (Images: [c] WorldAutoSteel) FSV BEV Steel Types as % of Body Structure Mass DP 500,600 11.8% DP 800 9.5% DP 1000 10% TRIP 980 9.5% TWIP 980 2.3% CP 1000-1470 9.3% MS 1200 1.3% HF 1500 11.1% Mild Steels 2.6% HSLA 450, BH 340,400 32.7% FSV BEV Manufacturing Processes As % of Body Structure Mass Stamping 41% Closed Rollforming 7% Hot Stamping 3% Hot Stamping 3% Hot Stamping--Laser Welded Blanks 9% Open Rollforming 2% Stamping--Laser Welded Blanks 38% Note: Table made from pie chart.
Caption: The 2011 Future Steel Vehicle was developed by the WorldAutoSteel organization in order to determine whether a vehicle could be made with new steel materials and new (or not widely used) manufacturing processes so that was mass, process and COSt efficient. (Photo: [c] WorldAutoSteel)
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|Author:||Vasilash, Gary S.|
|Publication:||Automotive Design & Production|
|Date:||May 1, 2019|
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