J-20 5th Gen Fighter Thread VIII

[Alfa_Particle]

Anywhere I can read about this more?

I believe the main literature on this technology would be this:


It is a case-specific paper on the FC-31 and how the design and manufacturing process outline brought numerous significant advantages such as weight savings and other neat stuff. I've done an extremely elementary translation of it:

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I'm not sure if there's any direct proof on it being used on the J-20A, but yes, they'd be absolutely stupid not to.

 

[enroger]

I believe the main literature on this technology would be this:
View attachment 150853

It is a case-specific paper on the FC-31 and how the design and manufacturing process outline brought numerous significant advantages such as weight savings and other neat stuff. I've done an extremely elementary translation of it:

Please, Log in or Register to view URLs content!

I'm not sure if there's any direct proof on it being used on the J-20A, but yes, they'd be absolutely stupid not to.

I doubt J-20A has substantial structural change such as this, when J-20 already has mature manufacturing lines and cost ameliorating well, retooling all of that just for marginal improvements on structural weight doesn't seems worth it

 

[Alfa_Particle]

I doubt J-20A has substantial structural change such as this, when J-20 already has mature manufacturing lines and cost ameliorating well, retooling all of that just for marginal improvements on structural weight doesn't seems worth it

I also doubt that they would opt for such a drastic change, but you'll have to admit,

Reduced:
- parts required by 50%
- overall weight by 38%
- parts weight by 26% (30% specifically for wing root parts)

...isn't exactly marginal. And that's just from optimising the fuselage.

 

[lcloo]

I remember slightly more than 10 years ago, there were photo release on 3D printed large components parts for J20. I think they already apply these large size 3D printed parts on building of early batches of J20.

 

[enroger]

I also doubt that they would opt for such a drastic change, but you'll have to admit,

...isn't exactly marginal. And that's just from optimising the fuselage.

I doubt it is 38% off overall weight as structural weight itself only accounts for 30%ish of overall weight. I guess it's really 38% off structural weigh, so roughly 10% off in overall weight.

Having said that I agree it is still quite substantial, it is a revolution in aircraft manufacturing

 

[Jason_]

A reduction of 38% structural weight in an aircraft is insane and should be only possible in poorly designed aircrafts like Tejas Mk1. A 5% reduction of structural weight is already very impressive.

 

[totenchan]

I remember slightly more than 10 years ago, there were photo release on 3D printed large components parts for J20. I think they already apply these large size 3D printed parts on building of early batches of J20.

This image? There's no indication that the J-20 actually uses this technique. It seems like a somewhat inefficient way to make these large bulkheads, especially since the shaping isn't that complex.

 

[Alfa_Particle]

I doubt it is 38% off overall weight as structural weight itself only accounts for 30%ish of overall weight. I guess it's really 38% off structural weigh, so roughly 10% off in overall weight.

Having said that I agree it is still quite substantial, it is a revolution in aircraft manufacturing

I think they did really mean a 38% overall weight reduction, but just the fuselage itself. The original text just said "weight reduction (减重)" with no specific keywords indicating that it's structural weight.

 

[latenlazy]

I doubt J-20A has substantial structural change such as this, when J-20 already has mature manufacturing lines and cost ameliorating well, retooling all of that just for marginal improvements on structural weight doesn't seems worth it

The J-20A does in fact have some structural changes though, like the fuselage hump, which suggests the odds of incorporating revised manufacturing processes are pretty good too. Chinese fighter procurement is also done in batches precisely to allow for incorporation of manufacturing improvements, as we saw with successive builds of the J-10s and J-11s.

 

[plawolf]

I also doubt that they would opt for such a drastic change, but you'll have to admit,

...isn't exactly marginal. And that's just from optimising the fuselage.

Firstly, I would assume that the weight reduction is using the original raw airframe superstructure weight as the baseline, not the total airplane weight. So, just pulling some numbers out of my butt for illumination, but if the original airframe superstructure weighed 10 tons, a 38% reduction would be 3.8 tons, which would only be a 12% reduction on the overall weight of the plane if it weighed 30 tons.

Secondly, while a 12% decrease in weight is still phenomenally good, it should also be noted that aircraft typically gain significant weight with block upgrades as additional equipment is added for increased performance and capabilities. So all of that is to say that the J20A might not weigh significantly less than the original J20. Depending on how much new and additional equipment they added, it may even come out slightly heavier despite the significant weight savings from the airframe production method change.