Students Prototype 3D Printed Bridge Competition

Civil engineering students from NJIT, Princeton, Stevens Institute of Technology, and three area high schools competed in a 3D-printed bridge competition at NJIT’s Makerspace that saw NJIT students taking home a first place prize in the “Stiffest Bridge” category. Both the collegiate and high school divisions were judged on five categories: best presentation, least support material, fastest assembly time, best aesthetics, and stiffest bridge. NJIT and Princeton tied for first place in overall score. 

More than 70 people attended the event in person while hundreds tuned in from home. It was a unique opportunity for civil engineering students who rarely get the chance to prototype their designs due to the sheer scale and capital intensity of most civil engineering projects, and NJIT’s engineering department plans to make it an annual event. The competition was modeled after the American Society of Civil Engineers’ steel bridge and concrete canoe competitions. 

It was a unique opportunity for civil engineering students who rarely get the chance to prototype their designs due to the sheer scale and capital intensity of most civil engineering projects.

“We wanted to do something that will involve new skills since additive manufacturing is becoming a more relevant structural technique,” said NJIT Assistant Professor of Civil and Environmental Engineering, William Pennock, who led the initiative to organize the competition. 

The strongest structures aren’t always the prettiest or the quickest to be constructed. Princeton and Stevens bested NJIT in those categories, taking home first place prizes in “Best Aesthetics” and “Fastest Assembly Time,” respectively. 

“The Princeton bridge was a thing of beauty. It had some resemblance to Roman bridges,” said Pennock of Princeton’s blue and white arch bridge. “For all the designs, there was an element of art to it. Bridge design is where civil engineers get to shine.”

Princeton’s bridge held 87 kg before breaking, and it was much lighter than the other two bridges. NJIT excelled where it mattered most. Their bridge was heavier, but much stronger, failing at a mass of 127 kg. A section of the deck failed, but the rest of the structure held together. Stevens Institute of Technology’s bridge failed at 47 kg. 

Teams used bolts or pegs to connect the parts of their bridges, but NJIT’s bridge deck “zipped” to the supporting walls of the bridge with triangular pegs coming out of the deck of the bridge that fit into corresponding holes in the bridge wall, allowing it to support a lot of weight. Teams printed their 3D parts beforehand and assembled the bridges on site. Stevens Institute of Technology had the fastest assembly time, but their structure turned out to be overly-reliant on the deck. 

“Given the strong competition and that this was the NJIT team’s first time doing this, I was at first worried that the host team could get crushed,” said Pennock. “However, the students pulled together, and their design proved polished and robust. Another thing NJIT did well was use these simple pin connections, pegs that slid very nicely into the holes in the bridge components. Their assembly was very fast.”

NJIT’s advantage was structural (pun intended). The school boasts the largest civil engineering department in the state and one of the biggest in the northeast. Its first-rate Makerspace also provides printing capacity and has built invaluable institutional knowledge. Resources are also expensive, and NJIT holds a bounty of donated materials. Not every civil engineering department can or is willing to undertake such efforts as NJIT has. 

The team of civil engineers had another advantage in Michael Brusca, a civil engineering student who previously purchased his own 3D printer for a hydraulics  lab experiment he designed on buoyancy when he printed different shapes to test their buoyant properties. He put that printer to good use again, helping to print a lot of the bridge parts in his basement. 

"I’m almost a senior and I haven’t built anything. For school projects it’s mostly calculations. It felt great to do something in my field." - Rukayeh Jaludi

Ultimately, the purpose of the competition was for civil engineering students to apply theory to practice and build something. 

“It was a great experience. I got really into it,” said Rukayeh Jaludi, one of the three civil engineering students on NJIT’s team, which also included Diego Cabrera. “I never actually built something. I’m almost a senior and I haven’t built anything. For school projects it’s mostly calculations. It felt great to do something in my field.”

“It’s really good for students to get into competitions. Some of the schools had difficulty getting kids to participate because they were worried whether they could win or not,” said Pennock. “We’re hoping that we’ll wind up filling a niche and expanding the education of civil engineers and looking forward to what will be the future of manufacturing.”

That future need look no further than NJIT’s own backyard. NJIT has cultivated programs designed to attract and retain local and underrepresented students, including the Center for Pre-College Programs, which works with over 4,000 pre-college students annually running camps and educational programs throughout the year.

The university also encourages enrollment in STEM fields, such as civil engineering. The Math Success Initiative, a partnership between the Office of the Mayor and the Newark Public School District, provides direct instruction and support to rising 12th graders and mathematics certified teachers. The Forensic Science Initiative, which is backed by a $1.4M grant from the Governor’s Emergency Education Relief (GEER) fund, features class work, lab work, field research, tutoring and college preparation counseling in one of New Jersey’s newest academic fields.

In the end, NJIT and Princeton tied in overall score and were both awarded the first place prize of a $1,000 3D printer. Stevens Institute of Technology won the second place prize of a $500 3D printer. 

Competing high schools included Applied Technology High School in Paramus, NJ; Middlesex Academy for Science, Mathematics and Engineering Technology in Middlesex, NJ; and the STEM Academy of the Oranges in South Orange, NJ. 

 

See the full list of awards:

Awards – High School Division

2nd Place - Best Presentation - STEM Academy of the Oranges

1st Place - Best Presentation – Middlesex Academy

2nd Place - Least Support Material - STEM Academy of the Oranges

1st Place - Least Support Material - Middlesex Academy

2nd Place - Fastest Assembly Time - STEM Academy of the Oranges

1st Place - Fastest Assembly Time – Applied Tech

2nd Place - Best Aesthetics - STEM Academy of the Oranges

1st Place - Best Aesthetics - Applied Tech

2nd Place - Stiffest Bridge - Applied Tech

1st Place - Stiffest Bridge - STEM Academy of the Oranges

Overall 2 – Applied Tech

Overall 1 - STEM Academy of the Oranges

Awards – Collegiate Division

2nd Place - Best Presentation - NJIT

1st Place - Best Presentation - Princeton

2nd Place - Least Support Material - Stevens

1st Place - Least Support Material - Princeton

2nd Place - Fastest Assembly Time - NJIT

1st Place - Fastest Assembly Time - Stevens

2nd Place - Best Aesthetics - NJIT

1st Place - Best Aesthetics - Princeton

2nd Place - Stiffest Bridge - Princeton

1st Place - Stiffest Bridge - NJIT

Overall 2 - Stevens

Overall 1 – NJIT + Princeton