I disagree with the statement that "Our job as engineers is to come up with cost effective alternatives to the use of cheap steel." That's only true for those of us who work for the plastics industry!
For those of us who work for OEMs, our job as engineers is to come up with the solution which best meets the performance, weight, cost, etc. requirements of the application. In some cases, that might mean composites. In other cases, it might mean steel. In still other cases, it might mean aluminum, or something else entirely.
As the article points out, steel technology has not stood still. The perception of steel as old technology (versus composites as new technology) does not reflect reality. For example, a new development called flash processing promises previously unheard-of strengths and ductilities for alloys like 8620 and 4130, and takes less than ten seconds. If the findings in this article are correct, this could be a major step in both bringing down the cost and improving the properties of high-strength steels.
Certainly it would be a mistake to rule out composites based on previous bad experiences, or worse yet, on tribal knowledge which may or may not have a basis in fact. But it would also be a mistake to assume that composites must be the wave of the future and to consign steel to the dustbin of history. Our responsibility as engineers is to weigh all of the factors, and make the decision which makes the most sense.
Timmy49: I agree. Regulators now are talking about 56 mpg (the number seems to keep changing) by 2025 and automakers are scratching their heads, trying to figure out how they'll do it. They'll need to eke it out in any way they can, and that goes for electric cars, as well as gas-burning vehicles. Since the EPA will calculate the corporate avergage fuel economy on miles-per-gallon-equivalents, automakers will need to raise the mpg-e on all vehicles, across the board. Composites are one of many reasonable ways to get an extra mpg or two.
Folks, while I agree that there are distinct advantages to the use of composites and plastics in the manufacturing process for the modern automobile we have to consider the negative influences that are the cause for delayed implementation. All things considered in this debate we each understand that "Composite Engineering and use is the future" of the automobile industry. Unfortunately this will not happen until we can eliminate the main drawback, "PRICE". Why would any intelligent and responsible company put everything at risk in order to be cutting edge? Why create a vehicle that will cost 30% - 75% more, just to be the leader when you can produce a safe, dependable and CHEAP alternative to any existing composite vehicle? The involvment of gov't won't help in the long run. It will only alienate the industry and the one that will suffer is the consumer. Our job as engineers is to come up with cost effective alternatives to the use of cheap steel. That way we all benefit.
While there's still money to be made doing it the old way, then the incentive to change is low.
Government mandates help. So does the consumer. A big breakthrough would be for a medium size company to come out with a composite vehicle that gained consumer acclaim quickly (right price, long distance, etc...). Then you'd see a huge push in innovation as the "big guys" scramble to get a piece of that pie.
Plasticmaster, thanks for linking to the UMTRI article. It's interesting that the barriers to the adoption of composites haven't changed much in the past 17 years, i.e. the same barriers continue to be in place. Corporate "learning" based on erroneous information continues to be a problem. I commented on this in another post.
I feel that composites are going to make their way into the automotive industry. With Washington's new proposal of 52.5 mpg by 2025, I don't see any other way of meeting this goal. I don't think they will replace everything, but they will be more predominant than they are now.
I have to admit, it would be nice to have a car with the same hosepower and 1/2 the weight. My one piece carbon fiber chassis could support pressure fomed body panels and a fiberglass steering coulmn.
Unfortunately this car would typically cost what formula 1 race car cost.
The reason we still use steel and aluminum is because it is relativley fast and easy to cut, form, machine, weld, cast, rivet, heat treat and paint. Composites from where I am standing require resin to be put into a mold, possibly wait for that to dry, more resin with reinforcing cloth of some type, some way of working out the bubbles, and then time for the whole thing to dry. After all that we get the use of our expensive mold. Where steel and aluminum parts spend seconds in a stamping die, composite parts may have to be "left to dry overnight"
This seems to me to be an inherent productivity challenge.
Perhaps with robots handling thermaly curing resins, spray in or precut reinforcement cloth and 2 part molds this process could be sped up.
It is hard to rethink the entire manufacturing process as it is expensive and automotive is a competitive market.
This will probably happen sometime in the near future, Composites that is, and is a better candidate for new car factories and designs...
Maybe thinking "outside the box" should include taking a page from the aerospace industry which has come a long way in their use of composite materials for a multitude of assemblies and components. While there have certainly been bumps along the way, a study of best practices and lessons learned from the Boeing 787 Dreamliner project, for example, should shed some light on what can and can't be accomplished and have applicability in the automotive sector.
What's the barrier to the adoption of composites? Is it cost? Is it performance. If there is a competitive advantage to using composites, one would guess some brand owner would adopt it to take the savings or performance advantages.
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