Transportation Design Project

[DangDangDingy]

Hi, I'm a student studying transportation design at uni and i've been given a project where i need to design a lightweight family vehicle. We've been told to especially look deep into new materials that are lighter than the materials currently in use that don't compromise the safety of the passengers. Since i have quite a restricted knowledge or materials i thought coming to an F1 forum might be a good place to start thinking of lightweight alternatives. From a structural point of view i need to find other materials that the chassis and other components would be made from that maintain the vehicles integrity. Any guidance or ideas on materials i could use are much appreciated =)

[simieski]

Hi,

Firstly as this is intended for a family car do you have budget constraints to worry about?

I'm not sure how new you are required to go, but obvious choices would be composites and exotic metals such as; carbon or aramid fibre reinforced plastics, fibre glass, honeycomb laminates, aluminium, magnesium, titanium etc. Most of those would be significantly more expensive than conventional materials and some also provide their own challenges, for instance aluminium is very light, but it can be prone to fatigue and along with magnesium can suffer badly from corrosion.


couple of links for you:

http://www.centennialofflight.gov/essay ... Tech40.htm
http://www.wired.com/autopia/2011/06/ne ... omposites/
http://www.hexcel.com/

[mep]

i've been given a project where i need to design a lightweight family vehicle. We've been told to especially look deep into new materials that are lighter than the materials currently in use that don't compromise the safety of the passengers.

I wonder who is giving such projects?
Tell this guy that you will use aluminium and steel for a family car.
Some body panels might be made from glass fibre reinstructed plastic.
The problem with carbon is not just that it is more expensive but also that it takes long time to make for example a chassis out of it. If you produce a family car you want to get a couple hundred or thousand cars rolling of your line every day. Carbonfiber is not useful for that. It is ok if you just want to build 1 car a week.

[DangDangDingy]

Thanks for the replies guys, very useful information. Im entering in a competition with this concept project and the end product wont be made, so costing isn't of the utmost importance. I'm designing a high end family vehicle for 2013 so materials can be as exotic as i'd like, within reason.

[Edis]

Most production cars are limited to steel unibodys due to cost, where subframes and other components can make use of aluminum. Some production cars have also used steel spaceframes, the advantages being that tool costs are so much lower than for unibodys making smaller series more realistic. Higher strength steels and better manufacturing processes can be used to reduce weight (ultra high strength steels are difficult to form - hence stainless steel is one option being looked at).

Higher end cars tend to use aluminum space frames, like Audi A8, R8, Ferraris and similar. The aluminum space frame is lighter than the steel space frame and the unibody, offers quite low tool costs and good flexibility which allows you to adapt the design for different models. The downsides are higher material cost and time consuming to manufacture, which means the cost per unit is high. But with a price tag close to 100k euros per car and small series of a few thousand cars per year they are realistic. One exception is the small Audi A1 (the old version), which was made using this design.

Carbon fibre monocoques are out of reach for most cars. Using prepregs and autoclaves we're talking very small series and very high costs, limited to high end supercars and racing cars like formula one. With dry automated lay ups and rapid injection moulding the technology would be possible to use in larger series/lower cost application. Still, the cheapest car currently offered with this type of chassi is the McLaren MP4-12C.

[Robbobnob]

if your really looking to stretch the boundaries, just a few exotic ideas of the top of my head

Making use of renewable and minimally invasive resources, using steam formed wooden vinear laminates for body panels. May not be cheap or cost effective at this point in time, but if enough capital is invested into the technology panels could be turned out relatively quickly.

Look at using renewable fibers for interior materials, such as hemps or corn husks etc, particularly trying to reduce the use of fossil fuel based materials.

Im not sure how detailed your design needs to be, but use of Crash structures, such as the ones employed in F1 might be beneficial.

again just a few suggestions from myself

All the best!

[Caito]

As far as I know Carbon Fiber is not the best material to absorb impact energy.


If you want a safe car you need a stiff "cage" to put the driver in, and crumple zones surrounding it.

[Edis]

As far as I know Carbon Fiber is not the best material to absorb impact energy.


If you want a safe car you need a stiff "cage" to put the driver in, and crumple zones surrounding it.

Carbon fibre is great at energy absorption in a crash, usually combined with aluminum or nomex honeycomb, but is pretty much excluded due to cost for a family car.

A lower cost option for energy absorption could perhaps be aluminum structures with a polymer foam core. Aluminum itself also got very good properties, infact it performs as well as steel but at half the weight. Aluminum foams are also interresting for crash structures.