South Dakota School of Mines and Technology
students took home second place in the Society
for the Advancement of Material and Process Engineering (SAMPE) 2018 Student Bridge Contest, by
designing a bridge weighing just 12.5 ounces that can carry a 2,000-pound load.
The competition, held in Long
Beach, Calif., pitted SD Mines researchers against 70 teams from 30
universities from around the world. Teams were tasked to design, build and test a 24-inch-long structural
composite bridge using fiber reinforced plastics and high-performance
materials. The annual event challenges teams to make bridges that carry a
specified load while also being as lightweight as possible. The Mines
bridge placed second in the inaugural year of the sandwich beam category
at SAMPE’s bridge contest.
“The SAMPE bridge competition is
a fantastic opportunity for students to develop some hands-on composite
fabrication skills and to see how the process side of composites engineering
truly impacts their final performance,” says Eric Schmid, SD Mines bridge team
member and SAMPE North America Young Professionals committee chair. “SAMPE
provides an excellent platform for students to demonstrate their capabilities,
and the chance to attend the SAMPE conference and bridge competition really
gives students a great view of how important composites are across many
different industries.”
Mines students engineered the
design of the bridge using a proprietary composite sheet material invented by a
team of researchers at Mines’ Composite and Nanocomposite Advanced
Manufacturing Center (CNAM)
and Composites
and Polymer Engineering (CAPE) Laboratory. By bonding the unique CNAM material, called Discontinuous
Fiber Thermoplastic Sheet (DiFTS), to the top and bottom of a
lightweight honeycomb core in a suitable thicknesses ratio, the students were
able to engineer the properties of the laminated sandwich structure to meet the
load requirements of the competition, while maintaining low overall
density. The DiFTS material incorporates short, recycled carbon fiber embedded in a thermoplastic
matrix, whereby uniform fiber distribution, significant fiber alignment,
effective fiber length retention, and thorough fiber encapsulation result in
high-performance properties using a low-cost process.
“It is not that CNAM has
developed a super-material; it is that we developed a low-cost, high
performance, environmentally sustainable composite that can be demonstrably
engineered to meet demanding load-bearing requirements, and which competes very
favorably against traditional high-cost carbon fiber composites,” says team
advisor, Professor David Salem, Ph.D., director of the CNAM Center and the CAPE Laboratory.
The SD Mines bridge team included
Matthew Phillips, senior in math
and mechanical
engineering; Schmid, a Ph.D. student in the Nano Science and
Engineering Program; and Krishnan Veluswamy,
a Ph.D. student in the Materials
Engineering and Science Program, who also won the 2018
SAMPE International University Leadership Experience Award. “It’s
exciting that this bridge was made from in-house materials developed at Mines,”
says Veluswamy. “This kind of material has
industrial applications across the board, from sporting goods to automobiles to
airplanes, because it’s strong, lightweight and inexpensive to manufacture.”
A sister center – the CNAM
Biomaterials Center (CNAM-Bio) – has recently been launched at SD Mines and is undertaking
research on plant based biodegradable plastics, natural biofibers and
biocomposites that could someday merge with this technology, further
enhancing the DiFTS environmental sustainability.
“The CNAM-DiFTS material itself
was developed over several years by CAPE/CNAM research scientists and
engineers, and as we enter the commercialization phase, it was certainly
gratifying to see its cost/performance advantages displayed so clearly at a
major conference and exhibition,” says Salem.
Both Schmid and Veluswamy also
recently attended the "It's
All About Science Festival”
at Sanford Research Center in Sioux Falls, where they
showcased their SAMPE bridge, a 3D printer in action and other examples of
composite materials for K12 students and their families. Approximately 3,000
community members attended the event, which included more than 50 booth
exhibits and numerous STEM demonstrations. Veluswamy also won an honorable
mention in the graduate poster competition for his work titled, “Thermoplastic
Fiber Reinforced Composites,”
which explained how the composite materials used in the SAMPE bridge were made.