Too many people think of wood as an old material, unsuitable for use today, merely because it's out of fashion compared with things like alloy steels, aluminium and, increasining, composites. But if they can make a crumple zone out of steel, aluminium, polystyrene, polyurethane foam, glass reinforced plastic, carbon fibre and other (quite wacky in their time) materials, why not correctly engineered wood.

As I said before, if you consider all the elements as if you were thinking about metal (e.g. pressed components welded together to form rigid/semi-rigid structures) then you are clearly an idiot. Just like composites require a different type of engineering to metal, so wood requires it's own methods. Consider it like that and, whilst wood isn't going to form the basis for the 'next generation' of daily motor vehicles, it doesn't seem quite so daft.

Quote from tristancliffe :

But if they can make a crumple zone out of steel, aluminium, polystyrene, polyurethane foam, glass reinforced plastic, carbon fibre and other (quite wacky in their time) materials, why not correctly engineered wood.

please correct me if I'm wrong, but I recall crumple zones as parts of the car that are preprogrammed by their structure to bend and to take the impact on themselves...
I have never seen bent wood...broken - yes...

Why does it need to bend? How do you think CF crumple zones (note: crumple isn't really the right word - it's more 'energy absorbing zone' - the crumple is merely an effective means to an end with sheet metal. Wood will flex a lot before it breaks - that takes quite a lot of energy, which it will store for a short period (slightly longer than the average accident occurs in). Once it's reached it's stress limits, fibres will begin to break, each one taking a certain amount of energy with it. Eventually they all break, and if you do your sums about right the same amount of energy can be 'absorbed' in a similar time/distance, in similar packaging.

Don't think in sheet steel terms. That's the norm, but it's not the only way to achieve the desired results.

If you haven't seen bent wood - take a thinnish plank of wood; a decent one that has been prepared, dried and sorted properly. Lean it up against a wall for a few days (in a humidity controlled, temperature controlled environment). When you come back it's own weight will have caused a not inconsiderable bend. No external forces, other than gravity.

Now, design a car. Use the thickness, densities and grain directions of the material to help you. Think about energy absorbtion. Think about what happens with loads, shocks, stresses and strains. Load paths, irregularities and all sorts of 'tricks' can be employed to put man in charge of the material, rather than being at the mercy of what you think should happen.

100 years ago you'd probably find people thinking that cars could never be made entirely from metal because it doesn't have any give - and who'd want to be stuck in a metal coffin surrounded by rigid metal?

Quote from tristancliffe :

Why does it need to bend? How do you think CF crumple zones (note: crumple isn't really the right word - it's more 'energy absorbing zone' - the crumple is merely an effective means to an end with sheet metal. Wood will flex a lot before it breaks - that takes quite a lot of energy, which it will store for a short period (slightly longer than the average accident occurs in). Once it's reached it's stress limits, fibres will begin to break, each one taking a certain amount of energy with it. Eventually they all break, and if you do your sums about right the same amount of energy can be 'absorbed' in a similar time/distance, in similar packaging.

Don't think in sheet steel terms. That's the norm, but it's not the only way to achieve the desired results.

If you haven't seen bent wood - take a thinnish plank of wood; a decent one that has been prepared, dried and sorted properly. Lean it up against a wall for a few days (in a humidity controlled, temperature controlled environment). When you come back it's own weight will have caused a not inconsiderable bend. No external forces, other than gravity.

Now, design a car. Use the thickness, densities and grain directions of the material to help you. Think about energy absorbtion. Think about what happens with loads, shocks, stresses and strains. Load paths, irregularities and all sorts of 'tricks' can be employed to put man in charge of the material, rather than being at the mercy of what you think should happen.

100 years ago you'd probably find people thinking that cars could never be made entirely from metal because it doesn't have any give - and who'd want to be stuck in a metal coffin surrounded by rigid metal?

All I have to say is, CONCEPTUALLY, I just don't see a "wooden" car having the same energy-absorbing, impact-withstanding, life-saving capacity as today's modern vehicles. At least not without complicated manufacturing processes to produce ribbed, laminated, and other modified wooden parts.

And who's to say the car pictured doesn't have basic ribbed, laminated and modified wooden parts.

The reason you don't see it is because you are limiting yourself to common wisdom - think laterally more! Anything is possible. Wood even makes a good material for an IC engine (well, parts of it, like pistons and rods. Not quite so hot on rings and liners!).

The car alone will cost a lot more than your average supercar I think. Probably a price equal to an all out, premium made luxury yacht.

Besides, I'd much rather have old-man-carver-joe design such a wooden supercar, rather than a 27 year-old average joe.

Green Peace will just pop it's tires anyways

Quote from tristancliffe :

And who's to say the car pictured doesn't have basic ribbed, laminated and modified wooden parts.

The reason you don't see it is because you are limiting yourself to common wisdom - think laterally more! Anything is possible.

I'm not saying it doesn't. I'm saying it's much easier and more economical to use a block of styrofoam in a bumper than laminated sheets of wood...

especially for those stupid soccer moms who love to bump other cars with their SUVs.

Of course it's easier (now that we know how to do it cost-effectively with metal), and I'm not suggesting for a moment that wood could compete in the normal car market at all, ever.

Odd how people feel safer surrounded by sharp metal and soft foam rather than a natural structural material which can withstand the forces of nature much more reliably than any man-made structure. Trees remain pretty intact in all but the most nasty weather. They might be plucked out of the ground, but even then they put up more of a fight than a car.

Quote from tristancliffe :

Trees remain pretty intact in all but the most nasty weather. They might be plucked out of the ground, but even then they put up more of a fight than a car.

Well, trees aren't hollowed out as much as possible to make room for 5 adults, 5 bags of luggage, an engine and other knick-nacks - so I think they have a slight advantage.

It could also be said that a solid steel cylinder the size of a tree could easily withstand a horrific storm that would otherwise destroy any wooden car...

That's a fair point, but trees are (usually) a fair bit narrower in cross section than a car

Anyway, the thing is, wood isn't such a bad material, and is perfectly acceptable for making boats, cars, engines, houses, desks, pencils etc.

Quote from tristancliffe :

That's a fair point, but trees are (usually) a fair bit narrower in cross section than a car

But that only means that a car is at an even GREATER disadvantage as it is larger but still has only a thin frame to protect it (relatively speaking.)

Quote :

Anyway, the thing is, wood isn't such a bad material, and is perfectly acceptable for making boats, cars, engines, houses, desks, pencils etc.

Point well taken, I just don't think its AS good a material at this point. Maybe later on tho - who knows?

The car is larger, so has a similar amount of material to resist, and a larger second moment of area.

I happen to think that wood (depends on the wood) is just fine if done right. Same weight, more strength, way better fatigue properties... But only in small, niche applications.

Quote from tristancliffe :

The car is larger, so has a similar amount of material to resist, and a larger second moment of area.

Yes, but whereas most of the trees material goes into absorbing an impact from any direction, not all of the structural supports of the car do the same (only, generally those parts parallel to direction of travel. Again, a solid steel cylinder made of the same amount of steel as a typical midsized car will withstand much more pressure without deformation...

By the way, just to clarify, I agree that wood could work just as well, I'm just saying it's not as easy at current - as you already know.

Not that much more force really. And a steel girder of the same size is a lot heavier - strength:weight is important, not just strength.

Quote from tristancliffe :

Not that much more force really. And a steel girder of the same size is a lot heavier - strength:weight is important, not just strength.

Same mass, not same size...

You did say size earlier...

edit:

Quote :

It could also be said that a solid steel cylinder the size of a tree could easily withstand a horrific storm that would otherwise destroy any wooden car...

Amount is neither mass nor size unless specified, and the only pre-specification was size, so I assumed size.

Had we been talking mass I'd say there is every change a decent wood could outperform 'standard' steels in most tests, assuming a vaguely similar layout of material.

Quote from Stang70Fastback :

Again, a solid steel cylinder made of the same amount of steel as a typical midsized car will withstand much more pressure without deformation...

amount

Quote from tristancliffe :

Had we been talking mass I'd say there is every change a decent wood could outperform 'standard' steels in most tests, assuming a vaguely similar layout of material.

vaguely similar?
if im not mistaken wood only becomes a true contender if you laminate several pieces together... how would you build a vaguely similar steel layout?

in some ways its a bit like a carbon fiber material that isnt all carbon yet

If I am right on this Doesn't each and every piece of wood have different densities and masses, if so then how can those idots have made a super car, that would have the worst weight distribution partly because there is no equal distribution on it anyway.

[stupidfanboyremark]
If you're so knowledgeable about wood, why don't you go make your own wood supercar Tristan!!!!
[/stupidfanboyremark]

and the designer whispers: "hey sorry mate I just picked the wrong material while rendering it wasn't supposed to be like that."

Ambitious but rubbish, says Jeremy.

Quote from anik360 :

If I am right on this Doesn't each and every piece of wood have different densities and masses, if so then how can those idots have made a super car, that would have the worst weight distribution partly because there is no equal distribution on it anyway.

Surely the randomness of wood would average out in all the pieces around the car to pretty much give whatever weight distribution you designed for?

Part of a car is all sorts of losses, resulting in hot engines, transmissions, brakes.. I wonder how they get rid of the heat as wood doesn't conduct heat very well.

Somehwo at some point i se big accident with this car with the driver inside beighn dead and,

full of woodsplinters(ouch@!!)[shouts dam You Al Gore]

Becaus i dont realy trust wood for beighn safe