If it is good for an Airbus Fusalage...

Most of us cannot afford to have an all carbon boat, or similar new age high tech composites. In fact, let alone affording one, i havent even seen one in reality.

I happened to find out recently that even companies like Airbus, are not yet ready to build the A380 fuselage entirely out of carbon, and they are claiming that carbon in this context is just black aluminum, providing very little if any weight savings over aluminum.

So, i wonder what ever happened to the good old aluminum as a hull material ,which costs just a fraction of the cost of carbon.

Airbus apparently is currently using fiberglass reinforced aluminum panels, sandwiched in multi thin layers.

I thought, if it is good for the largest passenger plane fuselage, something similar should trickle our way as an affordable new hull construction material.

 

It it is good for an airbus

Slight confusion here Omeron - I think the remark that 'carbon was just black aluminium' was what we call a 'throw-away' line. Possibly they meant that weight for weight there was little to choose between the two. However the strength and heat resistant properties of carbon over aluminium are far, far superior.
Carbon is the same mineral composite of graphite, and diamond, virtually 'rot free'; where aluminium - the commonest mineral on earth is at base bauxite - easily prone to oxidisation.
That gives the differnce in price - plus the relative rarity of carbon in industrial quantities.
But stand by for better informed sources...This forum is jam-packed with them....Oh, and welcome.

 

sounds like a good concept. im sure there would be some issues translating the idea to hulls and water, but i reckon with a bit of thought it could be a goer. cheap, light, robust, maybe struggles with impact resistance? may oxidise? though id say these problems would have already been partially if not absolutely solved buy those crafty french? The mans right, carbon really doesnt burn, (try it its fun) but not such a problem if your a boat.
my only query is with the production methods. i would assume an airbus fuselage is generally a pretty uniform section all the way down its length, and i would assume that these alloy panels are mass produced. ie the same panel is used 100 times in a plane, and there might only be like 20 different incarnations that go together like lego. i would assume that the rare bits (1 per plane) are probably not made in such an intricate manner. (the tooling etc. to build a panel that could measure up to a carbon one i guess would be fairly serious, and expensive??)
I have a full carbon boat. it was a one-off, and it was made from foam and carbon because it was light and quick to build off a jig, and relatively easy, strong, and has lasted pretty well, and really wasn't that expensive considering the performance of the boat. I can imagine if i wanted to build a one-off hull out of aluminium sandwhich panels, it would cost me a lot more. unless someone went a brought the technology to the masses (correct me if its already available.)
I can see a benefit in using it for mass-produced boats. like a laser, for instance, if you were going to churn out 190000 of them it may be very cost effective.
Are 29er centreboards and rudders still extruded alluminium? thats a case of larger upfront cost winning out in the long term, producing a product that is comperable to the cheap easy alternative. (bout the same weight; alloy versus fibreglass/foam)

also (im not sure if its what your describing) but ive been lucky enough to have a play with a bit of alloy panel, an light inner and outer skin with a fine aluminium honeycomb separating them, and yes it was very stiff, and strong, but it was still made up of basically alfoil, and so it was sensitive to nicks and scratches, dents, and pretty much any kind of load that was out of line with its design requirements. by the time i was finished with it it was a mangled wreck, i wouldnt have been able to destroy a comperable-weight comperable stiffness carbon/foam panel (so easilly)

 

Still around and still kicking. It dominates the small utility market, fishermen who want something cheap and zero-maintenance, and is also popular in larger speedboats and yachts (especially one-offs).

These materials are very stiff and light, but they're just not suitable for a boat- they're designed for the relatively uniform loading that an aircraft fuselage experiences, not the impact loads and pounding/slamming that a boat hull must survive. Adapting aerospace technology to marine applications is difficult and requires careful engineering of the structure based on a solid understanding of the technology and materials.

 

I know this may be contentious:

A leading designer (working for pay on one large project, and as a friendly adviser on a smaller project) recently told me that aluminum results in essentially no savings in cost to build one-off boats over sandwich fiberglass construction, and results in a substantial weight, volume, and maintenance penalty that you pay throughout the life of the vessel. He said that on most designs, they submit bid packages to both composite and aluminum yards, and the only time they go with aluminum is if the owner just really wants an aluminum boat.

On a complex one-off boat, we have talked to several aluminum and composite builders, including wood core composites, and there really is no cost advantage to speak of: the quality of the yard itself has a MUCH larger impact on price than the material.

On a multi-million dollar boat (which is not the price rannge we are talking about in this thread, I know), even the cost difference between foam-fiberglass and carbon-nomex from the same excellent yard is only about 15%, again far, far less than the spread between yards.

Therefore, I suggest that like everything else with a boat: Get what you want.

 

This says more about Airbus than it does about carbon composites or aluminum. Boeing's 787 fuselage is made of carbon composites, and Boeing has more than 500 orders for an aircraft that hasn't even flown, yet - a rather substantial vote of confidence in the future of composite airframes. Airbus has been forced to redesign their A350 with a carbon wing to compete with the carbon wing of the 787 because their biggest customers said very publically that they wouldn't begin to consider a modified A330 with its conventional aluminum structure. Both Airbus and Boeing have used carbon composites for their tail surfaces for years because that is the most weight-sensitive part of the aircraft.

"Black aluminum" refers to the practice of laying up a carbon composite using roughly equal numbers of 0, 90, and 45 degree fiber orientations to produce a nearly orthotropic material (so it has equal strength in all directions, like aluminum). This design practice typically has lots of cut-outs (say, for inspection plates) and drilled fastener holes, just like metal structures. If you use carbon in this way, it does come out being roughly equivalent to a metal structure.

But if you design and build composites correctly, aligning the fibers more with the major stress directions and producing larger monolithic components with fewer parts, then composites have significant advantages over aluminum.

 

someone said wHAt abt good old fashioned al al
well the majority of superyachts are built using aluminium, but their masts are carbon
Apart from cost, the building process is very very fast in alloy, but for one offs, very slow in carbon
Greens in UK probably the world leader in carbon yachts
As far as impact goes, when they built Shamon, the owner insisted upon, tests , a swinging heavily weighted pointed steel object was swung against test sections, with satisfactory passes
However a carbon fibre structure must be subject to far more , testing and quality control along the way that aluminium Aluminium is not just for dinghys as most of us know SeE some of the stuff in my gallery I have seen yachts built in the 50,s still going strong, only time will tell I spose for carbon
I,m not a scientist like you Tom, or an engineer, but, I know when I have built RIGHT

 

upon searching Shamon and Greens I came here, it is a most exciting website

http://www.greenmarine.co.uk/history.html

 

This fellow was touting the strength of a composite panel. To demonstrate he was repeatedly striking an approx. 1sq.ft. piece with a carpenters hammer.

The other fellow took the hammer, turned it, and easily drove the claw end through the panel.

Where I spend most of my time on the water, rocks are abundant. I'll take steel or aluminum over FG or composites 100% of the time.

Tim

 

Take a piece of marine grade alloy pl, form it to the modern u section forefoot of a boat and then try belt it in situ with a 20lb sledge, you get thrown off the plank, after 8mm plate you need enormous forces to form it When i ride in a 747 and see the wings beating: I often wonder How many millions of cycles does the structure go through,in a lifetime in the air and it still resists fatigue.