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Dec 10, 2012

Light Makes Right: Inside RMI’s Autocomposites Workshop


Car Start Button“Might makes right.” The popular aphorism has been around for centuries, and the perspective it offers for millennia. It’s been applied to everything from one nation conquering another to the National Football League. It’s also been applied to automotive engineering—the idea that bigger and heavier is associated with all sorts of desirable qualities, such as safety, strength, and durability.

Witness Volkswagen’s commercial “Door Thunk” for the 2012 Jetta. The narrator intones, “The solid thunk of the door on the Jetta: another example of Volkswagen quality. That’s the power of German engineering.”

But now, ultralight, ultrastrong materials—alternatives to traditional steel—offer the promise of an entirely different scenario. What if we replaced that heavy car door—and its “thunk”—with a superlightweight, superstrong door … one that effortlessly swings closed and shuts with nothing but a light click? What if light makes right?

RMI explored answers to those questions at our Autocomposites Workshop, held November 7–9 in Troy, MI, and attended by U.S. automakers, their suppliers, raw material producers, government representatives, and academia. One of RMI’s chief long-term goals is to wean the U.S. off of its dependence on oil. Not surprisingly, engaging the automotive sector is an important piece of that puzzle.

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Shifting the automotive sector away from oil dependence will involve a multipronged strategy, including dramatically increasing vehicle fuel efficiency and vehicle electrification. Both of those will be enabled, in part, through the adoption of ultralight, ultrastrong auto bodies made of advanced materials, since weight is tied to both fuel economy and the powertrain.

People looking at Carbon FiberCarbon fiber offers some of the best promise for making such a transition to lightweight-yet-strong vehicles, thanks to its superior strength- and stiffness-to-weight ratios. But while carbon fiber has already been adopted for bicycle frames and some niche sports car applications, broader adoption in the automotive industry has been slow to come. Besides, swapping traditional steel for an all-carbon-fiber auto body is a tall order.

The focus of RMI’s Autocomposites Workshop, then, was to identify specific subassemblies that would make excellent candidates for initial adoption, in order to gain some early industry traction. We worked together to identify a piece of a car—such as a door—that is already made from multiple smaller pieces (and held together with rivets, bolts, welds, etc.), and replace the entire subassembly with a single piece of molded carbon fiber that is both lighter and stronger than the original. By doing so, we would unlock elements of value that offset carbon fiber composite’s higher material cost, for example, demonstrating it as a viable option in the here and now, as well as in the future.

A car door—with an average weight around 50 pounds—turned out to be an excellent candidate. On the one hand are qualitative benefits that are very real yet harder to measure. A lighter door could be more easily opened when your hands are full. It would be less likely to slam shut unintentionally, such as when parked on a hill. The window frame could be thinner and the window larger, thus improving visibility (which affects the driving experience and safety).

Car Manufacturing PlantOn the other hand are quantitative benefits. A lighter door also means lighter hinges, attachments, and framing, further reducing an auto’s weight. If you swapped out all four doors of a sedan for carbon fiber composite versions, that cumulative weight savings alone could result in fuel savings of nearly $100 per year (net present value). Meanwhile, you’d incur an upfront material cost premium of about $800, yielding an eight-year return on investment. Vehicle fleets aside, most individual consumers aren’t willing to pay for much more than a three-year cumulative fuel savings in the purchase price of a vehicle, so the aforementioned safety and functionality benefits will play a critical role in the business case for carbon fiber composites.

Nevertheless, that business case is strong—a carbon fiber composite door stacks up very well against its business-as-usual steel counterpart, even at today’s material prices. There’s much yet to be done, however. Shifting to a new manufacturing paradigm that includes carbon fiber composites entails an investment in new tooling and equipment, and will require better design and analysis simulations to get maximum benefit and minimum waste from the material, as well as technological improvements to make carbon fiber repairable and recyclable.

At the end of the three-day workshop, participants identified key roles for business, government, and academia to play both in strengthening the initial business case for lightweight, composite-intensive vehicles and in paving the way for their widespread adoption in the longer term. One such proposed approach is a Detroit-based collaborative research and manufacturing center, with the express purpose of tailoring the material technology and manufacturing methods to automotive needs, in order to put the U.S. squarely on the forefront of a transformed global automotive marketplace built around lightweight vehicles.

One day—hopefully in the not-too-distant future—we’ll succeed in fostering a world where, when it comes to our cars, light does make right.

A full report of the Autocomposites Workshop proceedings, findings, and next steps will be available January 2013 at http://www.rmi.org/Autocomposites.

Highlighted Resources

Electric Vehicle

Lightweighting a Key to DOE's EV Everywhere Grand Challenge

RF Transportation

From Vision to Reality: Lighter, Stronger Vehicles



Crash Test Dummies

Size Matters


Some images courtesy of Shutterstock


Showing 1-9 of 9 comments

December 20, 2012

We are in the Sixth Extinction. Only progressive people can save the planet. This is not a political issue. This is a Homo sapiens survival issue.

Please study Jeremy Rifkin’s ideas at http://www.youtube.com/watch?v=82eUmqdSP60&feature=share&list=UUzJ9L7XB6xA2-B9upZGi2Mw Maybe we can avoid the extinction. Germany is the most advanced country at the moment. USA the least advanced.

This link and other links are on my website (http://treegrower.org/) athttp://treegrower.org/Extinction/Extinction%201.html James Hansen has definitive data that shows the sixth extinction is insured by burning fossil fuels. The keystone pipeline will insure a calamity. We are near 400 ppm greenhouse gas in atmosphere now; if we add no more the planet will still warm, until the land and ocean and sun are in temperature equilibrium again.

Hundreds of Articles on extinction are here: http://www.mysterium.com/extinction.html All these links are at http://treegrower.org/Extinction/Extinction%201.html

Why am I telling you? I have empathy for the biosphere.

Everybody can understand this emergency using simple arithmetic http://www.youtube.com/watch?v=cOrvGDRLT7A&feature=youtu.be

December 20, 2012

Has RMI looked into renewable carbon fiber production with lignin? We have a biorefinery that produces good quality lignin for melt spinning as a byproduct of renewable fuels and chemicals production. A good process to use the lignin for a value-added product is the last piece of the puzzle to utilize all the biomass. We're aware of the ORNL melt-spun fiber process. If there's interest and demand for these fibers we are ready to go!

December 20, 2012

Suppose - just suppose we started making the entire line of American automobiles with a majority of parts - of carbon fiber? Just like the racing world is beginning to discover that CF is much lighter (fuel savings) much safer (if done right) and even stronger than the steel construction we're using? You tell me ... or Calvin Lenman

December 27, 2012

We are building a car for the 2013 Shell EcoMarathon and would love to feature some RMI carbon. Amory, do you have a panel set we can demo in Houston? -BEL

Bradley Layton, PhD
Assistant Professor I Director, Energy Technology Program I Missoula College UM
909 South Avenue West I Missoula, MT 59801-7910 I bradley.layton@umontana.edu
Voice: 406-243-7865 I Fax: 406-243-7899 I http://ace.cte.umt.edu/

January 6, 2013

Carbon fiber is supposed to be very susceptible to exploding on impact - resulting in sharp carbon shards - unless blended with another material like kevlar. Yes, as stated, it's light, strong and stiff, but not very amenable to impact locations, such as doors, AFAIK. Any feedback from anyone on this sticky problem? Is there something I don't know?

January 10, 2013


In Reinventing Fire, our roadmap for transitioning the U.S. off coal and oil by 2050, we consider "alternative precursors" for carbon fiber production, including lignin. Zoltek and Weyerhaeuser have recently teamed up, in conjunction with ORNL as you mention, to convert black liquor from pulp mills into carbon fiber. Thus far they've had some success with melt-spun blends of PAN and lignin, whereas 100% lignin still faces some challenges from a material properties standpoint. We also briefly discussed lignin in a workshop we recently held in Detroit (www.rmi.org/autocomposites) to kickstart more widespread adoption of automotive carbon fiber composites. Lignin is an interesting option for transitioning to a fossil-fuel-free carbon fiber manufacturing paradigm but likely remains a longer-term option. There is compelling near-term opportunity in reducing costs of PAN-based carbon fiber and finding market entry points that offer sufficient value to offset its higher cost relative to the steel it would replace.

Greg Rucks
Rocky Mountain Institute
(970) 927 7312

January 10, 2013


The long-term vision of the Autocomposites Workshop is in fact to achieve widespread adoption of automotive carbon fiber composites, ultimately enabling mainstream carbon fiber composite autobodies. The increased strength and safety potential of this material are among the reasons it critically underpins RMI's roadmap to a fossil-fuel-free U.S. transportation system by 2050.

Greg Rucks

January 10, 2013


Keep up the good work bringing in and supporting the next generation of energy efficient vehicle designers with EcoMarathon. Because we are a nonprofit, we aren't in the carbon fiber business per se. We do however have have a for-profit spinooff that came out of some our Hypercar work in the early 2000s called Fiberforge (www.fiberforge.com).

Greg Rucks

January 10, 2013


It is true that carbon fiber composite can disintegrate and pulverize on impact. It is exactly this characteristic that lends it such unparalleled crash safety potential, because each shard that breaks off dissipates some of the crash energy of impact. Shatter-proofing is by no means an unprecedented challenge in the auto industry. Good design can very easily prevent shards from becoming harmful in crash conditions.

Greg Rucks

Greg Rucks

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