The Walmart Advanced Vehicle Experience is a prototype tractor-trailer developed to demonstrate the possibilities of future transport. Innovation and collaboration were key drivers in the concept’s development.
Peterbilt worked with several partners on the uniquely shaped truck, which achieves a 20% aero improvement compared to previous models. Highlights include a microturbine-powered, series hybrid-electric drivetrain from Capstone Turbine Corp. that doesn’t require a cooling module, thereby enabling the truck’s aerodynamic design. The cabin features a centered driver’s seat and an advanced human-machine interface enabled by Qualnetics connectivity technologies; the configurable electronic dashboard consists of three tablets that provide performance and other data.
But the truck is not the only place where innovation reigns. The trailer body is built almost exclusively with carbon fiber, and it incorporates other technologies such as advanced adhesives and low-profile LED lighting from Grote.
“There are going to be many who question the practicality of this great material [carbon fiber] in the equipment that we use today, and to be fair they have a point,” said Adam Hill, Vice President of Product and Sales Engineering at Great Dane. “Today we pay under $1 per pound for steel, we pay between $1 and $2 per pound for aluminum, but 10 years ago carbon fiber was $150 per pound; today, it’s about $10 per pound. So, if it continues its historical trend, forward-thinking companies will start looking at the possibilities of materials like carbon fiber today.”
The “practicality” of using carbon fiber becomes clearer when one considers the substantial weight savings achieved compared to conventional materials and construction.
“Walmart’s typical fleet trailer that they run weighs about 14,400 lb. This [concept] trailer weighs about 11,400 lb, so it’s 3000 lb lighter. But we put some things on this trailer that Walmart normally doesn’t do, like the [SAF-Holland] air ride suspension and the lift axle on the front,” Hill explained to Automotive Engineering. “Had we built this trailer just like a Walmart trailer except in fiber composite, [it’d be] 4000 lb lighter. It would have weighed about 10,300 lb, built to the exact Walmart fleet spec.”
As Hill explains in greater detail in this Automotive Engineering video, the development program that began with Walmart more than three years ago initially called for “radical aesthetics,” lightweight components, and the latest technology from suppliers.
“It was never intended to haul any freight, it was never intended to have a load put in it, it was never intended to be registered for operation,” Hill explained. But then Walmart “raised the bar” on the program’s goals and called for a road-ready trailer—not just a showpiece.
Roush Engineering manufactured the convex front nose of the trailer, which is made of a lightweight core and clad with solid carbon fiber. The shape enhances aerodynamics while maintaining cargo capacity.
Fiber-Tech Industries and Milliken teamed to produce the single-piece, 53-ft (16.2-m) carbon-fiber panels that met the program’s strength and weight bogeys for the sidewalls and roof of the trailer. The solid, 53-ft one-piece floor, also supplied by Fiber-Tech and Milliken, is a lightweight glass mat material—not fiber composite—and is capable of withstanding forklift loading.
“If you can make a fiberglass panel, you can make a fiber composite panel,” Hill said. “It’s really the same construction.”
Assembly of the trailer was expedited by the preassembled large panels. “Construction went quick; it took very little labor,” Hill said. “Typical trailer construction takes a lot of small components put together to make a large component. But when all of the components come into the factory preassembled in large panels, it takes very little time to do that assembly.”
Adhesives are used extensively in the trailer construction. “The mechanical fasteners are really not necessary,” Hill explained. “But lacking some of the necessary tooling that we needed to administer the right volumes of glue, to put the correct clamping pressure on there, we put the mechanical fasteners in there so that we would be assured there would not be any problems.”
Watch this Automotive Engineering video for more details on Great Dane’s lightweight composite trailer.Continue reading »