|Quoting Astuteman (Reply 39):|
Quoting FlyDreamliner (Reply 32):
It's also substantially heavier than the boeing carbon composites used in 787
In reality, the fuselage structure weight is as dependent on the METHOD of construction as it is on the material.
Quoting Gigneil (Reply 37):
No, it isn't. That's it. Al-Li is as light as and can be lighter than the CFRP tape Boeing is using.
I'll be interested to see what Airbus can come up with.
When the A350 was as fat (or thin) as an A330, Airbus maintained that the difference between Al-Li and CFRP would be "minor". It was suggested here that this might reflect in large part different methods of construction as is reflected in Astutemans comment on the method of construction.
Now that the A350 has put on diameter, it presumably contains more metal to cope with the extra circumference, but presumably this will be offset to a greater or lesser extent by the metal removed because the stiffness of a fatter structure is inherently greater.
RE: Airbus A350/370 What Do We Know So Far? (by Astuteman May 10 2006 in Civil Aviation)
had this section from Astuteman
"Riveting and Bonding will add substantial weight to an aircraft structure compared to welding (any structure, for that matter)......
You have both
a) an overlap of the panels (i.e. duplicate material), and
b) a material thickness increase over what would be necessary with a welded joint to compensate for the holes in the parent panels. That increased thickness may be for the entire panel, otherwise you would need even more panels and more joins to accommodate differing material thicknesses.
The weight saving will vary dependent upon component size. But it will be substantial, trust me. It could easily be 10% (Ignore the weight of the fasteners + bonding materials, they're not the weight drivers)"
That was from 10 May 2006. Assuming that this bet is still on (I think Astuteman was then only writing about A350 thin and opposed to A350 fat but presumably the same holds) we should soon be able to see how construction methods will affect the overall weight.
Let us hope that the story will have a happier ending than the classic tale of weight loss, "The truth about Pyecraft" - H G Wells.