so here is my question.

General Composites Discussions Composites Talk
#1

as many of you may know the airforce is phasing the f-15s out for the fa 22. the f22 is mostly composite. its been around since 84. my first dealing with one was of course grounded cuz it cracked.

heres my question. the f-15 is a pretty solid platform being mostly al and ti construction. almost every composite component on the f15 fatigues and leads to failure. the radomes speedbrakes elevators ect.

how is graphite constuction compared to metal construction as far as life fatigue so to speak… do you think the multirole fighter will be up to the job in say 2050??? im not so sure. even the f15 has its problems but the 22…

even the kommy bastard su-33 is a half composite and half metal airframe… it is quite possible the most expensive and most problem ridden aircraft for the reason that it cant stay together.

or are we overlooking the fact that lockheed has now grabbed uncle sam by the nuts with maintenance fees… :slight_smile:

just curious. i know composites are stronger and lighter than metal. but for lasting a long time im doubtful… ive seen many a over “g” repairs and even once had a pilot perform his own structural repair as a lesson under my supervision.

#2

if we’re (as a world) still depending on manned combat in 2050 we shouldn’t be allowed to touch weapons.

#3

Yep… i fully agree with that statement. Pilots will be phased out in the next 10 years i bet.

As far as fatigue and life of a composite aircraft… the engineers have software programs that tell them most all of that stuff.

That is what i love about “CAD” programs such as SolidWorks… they can tell you how to better design each part according to stress and load,etc. You can virtually start drilling large holes in parts and then analize the drawing to see how those holes effect the part or entire assembly.

If i knew wtf i was doing with those type of programs it would be cool to design and build an all carbon fiber sportbike motorcycle frame.

#4

find someone over at www.ccm.udel.edu and ask. I’m sure someone knows :slight_smile:

#5

I teach employees to make F22 parts and never a single problem of any kind.
Quite the opposite with most parts we’re making these days. Many metal components being replaced with composite versions.
Same for heli rotor blades. Composites are much more resistant to fatigue and damage.
F22 part

Blades for the president

#6

What about in 20 years? :slight_smile: