COMPOSITE MATERIALS IN AIRPLANES - Weight reduction is the single greatest advantage of composite material usage. A lower-weight plane is more fuel-efficient because it requires less fuel to propel itself forward - Composite materials — especially those made from glass fibers, carbon fibers, and Kevlar — are widely used in the aircraft industry. They are stronger and lighter than aluminum, the metal that's most commonly used in aircraft bodies. Composite materials are so named because they consist of two or more materials. The composites used in planes consist of fibers suspended in a matrix of epoxy resin. The Boeing 787 Dreamliner was the first commercial airplane to be constructed from 50% composite materials, mostly carbon fiber composites. The remainder of the plane consists mostly of aluminum, titanium, and steel. Composite materials have revolutionized aviation, but their use does present some engineering and maintenance challenges. Composites are also incredibly strong and as a result have a higher strength-to-weight ratio, also known as specific strength, than the metals used in making aircraft. Composite materials aren't prone to corrosion due to harsh chemicals, and they're resistant to many highly reactive chemicals.

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Composite Materials in Airplanes

Advantages and Disadvantages of Using Composite Materials in Airplanes

Weight reduction is the single greatest advantage of composite material usage - a lower-weight plane is more fuel-efficient because it requires less fuel to propel itself forward

BY SARINA HOUSTON

Composite materials — especially those made from glass fibers, carbon fibers, and Kevlar — are widely used in the aircraft industry.

They are stronger and lighter than aluminum, the metal that's most commonly used in aircraft bodies.

Composite materials are so named because they consist of two or more materials.

The composites used in planes consist of fibers suspended in a matrix of epoxy resin.

Fiberglass is a composite material made of glass fibers and epoxy resin. It was first used in aircraft, by Boeing, in the 1950s.

The Boeing 787 Dreamliner was the first commercial airplane to be constructed from 50% composite materials, mostly carbon fiber composites; All Nippon Airways put the first 787 into service in October 2011.

The remainder of the plane consists mostly of aluminum, titanium, and steel.

Composite materials have revolutionized aviation, but their use does present some engineering and maintenance challenges.

Here is a roundup of the advantages and disadvantages of using composites in aircraft.

Advantages

Weight reduction is the single greatest advantage of composite material usage. A lower-weight plane is more fuel-efficient because it requires less fuel to propel itself forward.

Composites are also incredibly strong and as a result have a higher strength-to-weight ratio, also known as specific strength, than the metals used in making aircraft.

In addition, they resist compression and don't easily break under tension.

Composite materials aren't prone to corrosion due to harsh chemicals, and they're resistant to many highly reactive chemicals. They can also handle wide variations in temperature and exposure to severe weather.

Another big advantage of composites is their design flexibility: They can be made into just about shape.

And a single, oddly shaped piece of composite can replace many pieces made of other materials. That helpful characteristic cuts down on maintenance and so can reduce costs over the lifetime of a plane.

Once a composite piece has been formed, it maintains its shape and size.

That's important in the aircraft industry because it means the essential parts of a plane made out of composite materials won't grow, shrink, or change form as environmental conditions vary.

Disadvantages

Perhaps the biggest disadvantage of composite materials for aircraft and component manufacturers is their higher initial cost compared with metals.

The greater cost is largely due to the price of the fibers and the complicated process required to make the finished materials.

It can be difficult to tell when the interior structure of a composite aircraft piece has been damaged. That makes inspections difficult and more costly.

One issue that comes up during inspections is delamination — when layers of composites separate.

The biggest cause of delamination is an impact to the composite piece. Water can infiltrate a piece that has experienced delamination, and the problem will get worse as the water freezes and thaws.

Standard aircraft composite materials do not conduct electricity and so, unlike aluminum, cannot prevent lightning from being directed to a plane's fuel tanks.

That problem was corrected for the 787 by incorporating wire mesh into the composite.

Finally, the resin used in composite materials weakens at temperatures as low as 150 degrees Fahrenheit, and a temperature above 300 degrees might result in aircraft failure.

When composite materials burn, they give off toxic fumes and micro-particles into the air, causing health risks.

For all of those reasons, fire prevention is crucial on planes built with composites.

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ALL-TERRAIN ADVENTURE TIRES WITH KEVLAR - Kevlar is meant to be five times stronger than steel on an equal-weight basis, which means it is extraordinarily strong for its weight and is actually used in the process of making bulletproof armor. Since Goodyear currently has the exclusive license to use the name "Kevlar" in connection with passenger car tires, the Goodyear Wrangler All-Terrain Adventure tires are some of the best on the market. Wrangler is built much like any other steel-belted radial tire, except a layer of Kevlar replaces the usual layer of nylon cord. Replacing the nylon layer with Kevlar results in a tire that's lighter, stronger and more puncture-resistant than before, and durability is also improved, which allows Goodyear to include a 60,000-mile tread life limited warranty on the new tire.

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All-Terrain Adventure Tires with Kevlar

Review of Goodyear Wrangler All-Terrain Adventure Tires with Kevlar

by Jason Fogelson 

Not all tires are created equally.

Case in point, the Wrangler All-Terrain Adventure tire from Goodyear Tire & Rubber with Kevlar are a great choice for drivers who spend most of their time on the pavement but want to have the right set of tires for occasional off-road use, with minimal sacrifice in comfort, durability, and capability. 

The Wrangler name is a familiar one — it's been emblazoned on various Goodyear tires since at least 1991 according to the Goodyear website, but the big innovation in this all-new version is the addition of Kevlar, which is the trade name for an aramid fiber manufactured by the DuPont company.

Kevlar is meant to be five times stronger than steel on an equal-weight basis, which means it is extraordinarily strong for its weight and is actually used in the process of making bulletproof armor.

Since Goodyear currently has the exclusive license to use the name "Kevlar" in connection with passenger car tires, the Goodyear Wrangler All-Terrain Adventure tires are some of the best on the market.

Lighter, Stronger, and More Puncture-Resistant

Wrangler is built much like any other steel-belted radial tire, except a layer of Kevlar replaces the usual layer of nylon cord.

Starting from the outside, there's the tread, then a layer of Kevlar (one layer for standard load tires, and two layers on the Light Truck or "Pro Grade" version), then two steel belts.

Replacing the nylon layer with Kevlar results in a tire that's lighter, stronger and more puncture-resistant than before, and durability is also improved, which allows Goodyear to include a 60,000-mile tread life limited warranty on the new tire.

The new Wrangler also gets a new tread pattern that is appropriate for four seasons in most sizes, and even wins the treasured "mountain-snowflake" emblem that signifies approval for winter driving.

The tread is designed to grip on loose surfaces and includes open shoulder blocks and special ridges deep in the tire grooves that are said to shed dirt and snow as the tire rolls, making them "self-cleaning" during operation.

Wrangler also benefits from Goodyear's "Durawall Technology," which imparts strength and cut resistance to the sidewalls, in excess of normal street tire specs.

This additional toughness will be especially welcome for SUV drivers who spend time on rocky terrain, as the sidewalls are a particularly vulnerable part of the tire during off-roading, even at low speeds.

A Personal Story of Testing On and Off-Pavement

I got to drive a 2013 Chevrolet Suburban equipped with a set of Wrangler tires during a recent trip to Colorado Springs, Colorado.

Goodyear brought a group of automotive journalists and tire retailers to the mountain town in order to experience the adventure aspect of the new Wrangler.

I drove on city streets, highways and curvy paved roads, fully expecting a noisy ride from the assertive tires.

I was pleasantly surprised to find that the Wranglers were as smooth and quiet as most other on-road tires I've driven on recently, and the sense of grip and confidence was up there with the best.

Then it was time for a little bit of light off-roading — actually, more like dirt-roading than genuine off-roading.

Still, the Wranglers impressed, riding across dirt and light mud with little drama at all; the Durawall Technology seems to work well, imparting great road feel to the steering wheel without stiffening up the ride beyond comfort levels.

A final test came in a short autocross in a big (empty) parking lot. Goodyear set up a short tight autocross route, delineated with orange cones, and brought out a water truck to wet a few of the corners for us.

They spooned a set of Wranglers on two white Ram 1500 pickup trucks, and a set of competitor's tires on two black Rams, and then let us drive them back-to-back.

The Wrangler-shod Rams greatly outperformed the competitor-equipped Rams in the wet stuff, keeping their footing even under heavy acceleration during corner maneuvers.

I killed a few cones in the competitor tire vehicles, even when trying to maintain a sane speed through the curvy portions of the autocross.

The most significant advantage that I felt in the Wrangler was in the hundred yards or so after the water obstacle.

The Wrangler instantly shed the water from its grooves and performed beautifully. The competitor slid out in the first curve after the water hazard, seemingly retaining water later through the drive.

The autocross ended with a controlled stop, slamming on the brakes to full and allowing the ABS system to bring the truck to a halt.

I noticed a slight advantage for the Wrangler in this test as well, though not as significant as the wet surface test revealed.

Conclusions and recommendation

It's very difficult to evaluate a new tire, but the Goodyear Wrangler All-Terrain Adventure with Kevlar is a solid innovation in tire technology.

The advantages of a Kevlar layer (or two) are obvious, and the performance of the Durawall Technology and new tread pattern were demonstrated well enough to impress.

Drivers will be especially pleased with the quiet, confident on-road performance of the Wrangler since that's where most of us spend 90% or more of our time driving.

And even though it has nothing at all to do with performance, the beefy Wranglers were pretty good-looking tires, too — especially with the raised white lettering exposed to the outside.

Goodyear is a premium tire brand, and Wranglers look the part.

There may be more appropriate tire choices for serious rock crawling and specialty off-roading, but those tires are difficult to live with on a day-to-day basis.

However, the new Wrangler All-Terrain Adventure with Kevlar tires are great for everyday use on your SUV, especially with its 60,000-mile tread wear warranty. See the Manufacturer's Site to find a local dealer for your replacement Wrangler tires today!

https://www.liveabout.com/goodyear-wrangler-allterrain-adventure-kevlar-review-3160646