lightsaber wrote:Next generation:
1. GFRP wings (not CFRP).
Can someone comment on how much better GFRP is as an aircraft construction material than CFRP? Wikipedia does not help much.
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lightsaber wrote:Next generation:
1. GFRP wings (not CFRP).
Slug71 wrote:What Balerit said.
But try reading up on FMLs(Fiber Metal Laminates), ie GLARE. I know its slightly different since it's using metals instead of Polymer. But I assume its reasons are similar. Some big improvements are being made to the manufacturing process of C(carbon)FMLs currently. I think carbon will pretty much replace glass going forward. Especially since advancements in carbon like Carbon Nanotubes are being made too. Theres a few good links in the "2025ish A380-900NEO" thread here. I think theres a good chance we'll see aircraft using both CFMLs and CFRP in the future.
Balerit wrote:The only thing about fibre glas construction is it is cheaper and less hazardous with regards to fumes during the manufacturing process otherwise carbon outperforms it in every other aspect.
Balerit wrote:We still use GFRP to mean glass fibre reinforcing and CFRP as carbon fibre reinforcing - also known as graphite. Kevlar is the trade name for a third reinforcing plastic that is known as a para-aramid synthetic fiber. Glare is a sandwich construction made up of sheets of fibre glass and aluminium bonded together and seems to be making a comeback at Airbus.
https://www.compositesworld.com/blog/post/the-resurgence-of-glare
Balerit wrote:Interesting thoughts Lightsaber, unfortunately I'm retired now so I not up to scratch on the very latest techniques but the Russians have some interesting manufacturing methods as well. Another thought comes to mind and that is the yacht building industry seems to be the leaders in this tech.
JayinKitsap wrote:On several buildings I am involved in are using panels of 26 ga steel (or aluminum) sandwiching a foam core. They work great and are quite lightweight. Glare or a composite skin on a light core insulation would have amazing performance, provided the bond of the skin to the core isn't weak. Thermal expansion can play havoc with that bond.
WIederling wrote:JayinKitsap wrote:On several buildings I am involved in are using panels of 26 ga steel (or aluminum) sandwiching a foam core. They work great and are quite lightweight. Glare or a composite skin on a light core insulation would have amazing performance, provided the bond of the skin to the core isn't weak. Thermal expansion can play havoc with that bond.
quite some time ago I worked with this stuff:
https://www.metawell.com/en/
(Aluminium sandwich panels in a "corrugated cardboard" style )
JayinKitsap wrote:On several buildings I am involved in are using panels of 26 ga steel (or aluminum) sandwiching a foam core. They work great and are quite lightweight. Glare or a composite skin on a light core insulation would have amazing performance, provided the bond of the skin to the core isn't weak. Thermal expansion can play havoc with that bond.
lightsaber wrote:What matters is there is another generation of reinforced plastic coming down the pipeline for wings, woven bodies, and panels. On new structures, it saves weights. In some cases, allows better geometry which saves weight.
Please put on your stress engineer and material scientists hat and think of what you would improve in CFRP to make a next generation airliner cheaper to manufacture and lighter. What would you change? If you have made aerospace parts you are well aware of how much weight ends up in the final structure to ensure long life via damage and fatigue resistance. I'm talking everything from making the structure more rigid so that the Young's modulus imbalance doesn't matter or with the addition of sacrificial layers and that heavy epoxy coating the outside parts receive.
'Weight Assessment for Fuselage Shielding on Aircraft With Open-Rotor Engines and Composite Blade Loss' (http://www.tc.faa.gov/its/worldpac/techrpt/tc13-34.pdf) wrote:Since new open-rotor designs will likely use composite fan blades and airframes, composite materials were utilized for this study. A triaxially-braided composite of TORAYCA T700S fibers and CYCOM PR520 toughened resin was selected. The braid architecture was composed of 24 k tows in the 0deg direction and 12 k tows in the +/- 60deg directions with the same fiber volume in each direction so that the in-plane stiffness properties were quasi-isotropic. This particular material and fiber architecture was selected for several reasons. First, due to the quasi-isotropic properties, each layer in the composite is identical, and delamination due to inter-ply property mismatch is minimized, resulting in good impact properties. Second, from a manufacturing point of view, this material is both practical and affordable. Lastly, considerable mechanical property and impact test data, as well as analytical material modeling results are available for this material (Refs. 2 to 8). The same braided composite system was used for both the notional blade and shielding structures. This material may not be optimal for a composite blade design, but its relatively high toughness provides for a conservative estimate of shielding requirements. Because of the test verification available for the material modeling, there is a relatively higher level of confidence in the analytical results than is typical for conceptual studies.
Scientists make strong, super-tough carbon sheets at low temperature (https://phys.org/news/2018-05-scientist ... heets.html) wrote:"In contrast, our process can use graphite that is cheaply dug from the ground and processed at temperatures below 45 degrees Celsius (113 degrees Fahrenheit)," said Dr. Qunfeng Cheng, professor of chemistry at Beihang University and a corresponding author. "The strengths of these sheets in all in-plane directions match that of plied carbon fiber composites, and they can absorb much higher mechanical energy before failing than carbon fiber composites."
lightsaber wrote:Balerit wrote:Interesting thoughts Lightsaber, unfortunately I'm retired now so I not up to scratch on the very latest techniques but the Russians have some interesting manufacturing methods as well. Another thought comes to mind and that is the yacht building industry seems to be the leaders in this tech.
Yes, the Russians have done much for cold cured composites. They remain the leader in Titanium welding and some other titanium processes.
AIRWALK wrote:Which is interesting considering the MiG-25 used Steel instead of Titanium because they were having difficulty working with it back then! While the SR-71 was mostly Titanium, actually acquired from the USSR.