How to Spice up Your Balsawood Bridge Competition (Other)

J Carroll; Kyle Mitchell

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Conference: 2022 ASEE Annual Conference & Exposition
Location: Minneapolis, MN
Publication Date: August 23, 2022
Start Date: June 26, 2022
End Date: June 29, 2022
Conference Session: PCEE Session 3: Robotics and Design Competitions
Page Count: 20
DOI: 10.18260/1-2--41146
Permanent URL: https://peer.asee.org/41146
Download Count: 626

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J Carroll Saint Louis University

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Associate Professor and Chair, Department of Civil, Computer, and Electrical Engineering

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Kyle Mitchell Saint Louis University

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Abstract

Balsawood bridge competitions are the typical outreach activity for many civil engineering programs across the country. K-12 students are required to construct a balsa wood bridge based on given specifications, and then they load those bridges until failure with weights or sand. The winning bridge is generally the structure with the highest strength to weight ratio (i.e. load supported:bridge weight). Unfortunately, such competitions have remained relatively unchanged for decades and have lost popularity as a result of the competition’s somewhat slow pace. Saint Louis University held a traditional balsa wood bridge competition for eight consecutive years, but completely overhauled their format during the 2018-2019 academic year to increase the excitement and suspense of the competition. The new format includes three unique features: a tournament bracket, trivia competition, and various levels of instrumentation and technology. First, the competition uses a 32-team tournament bracket for all bridges. Bridges are “seeded” into four 8-team brackets based on a combination of previous year’s results and a random number generator. Two bridges are loaded simultaneously on two different load frames by placing 2 lb sandbags in a suspended bucket for each match. At the time of failure for one bridge, the other bridge is unloaded and removed from the load frame; it advances to the next round. This better simulates the repetitive loads that real bridges encounter. This process continues until there are four teams remaining (i.e. the “Final Four”). At that point, the loading procedure returns to the traditional format where each bridge is loaded individually by adding sand to a suspended bucket until complete failure. The four bridges are evaluated and the champion is crowned based on strength:weight ratio and several other factors. Second, a trivia competition was added to address the down time when the bridges are being placed in the load frames. Each team is given an iClicker2 upon check-in to answer questions throughout the competition. The trivia competition includes approximately 30 questions related to civil and structural engineering and one question is revealed between each match along with four multiple choice answers. Teams are given 30 seconds to answer each question. Lastly, various forms of instrumentation and technology were used to enhance the competition. An electronic load cell is used between the bridge and the loading bucket, which allows the supported load to be monitored live during the event and the maximum load on a bridge recorded just prior to failure. The load is also projected on large LED displays for the audience to see. Furthermore, the COVID-19 Pandemic required the competition directors to rethink how to engage an audience remotely. Zoom was used with multiple cameras from different locations that were selectively broadcast into a video stream: a technique that can also be used for in-person competitions. This paper will provide a detailed overview of the competition and its features along with several lessons learned and suggestions for others interested in spicing up their balsa wood bridge competitions.

Citation
Format

Carroll, J., & Mitchell, K. (2022, August), How to Spice up Your Balsawood Bridge Competition (Other) Paper presented at 2022 ASEE Annual Conference & Exposition, Minneapolis, MN. 10.18260/1-2--41146

TY - CPAPER
AB - Balsawood bridge competitions are the typical outreach activity for many civil engineering programs across the country. K-12 students are required to construct a balsa wood bridge based on given specifications, and then they load those bridges until failure with weights or sand. The winning bridge is generally the structure with the highest strength to weight ratio (i.e. load supported:bridge weight). Unfortunately, such competitions have remained relatively unchanged for decades and have lost popularity as a result of the competition’s somewhat slow pace. Saint Louis University held a traditional balsa wood bridge competition for eight consecutive years, but completely overhauled their format during the 2018-2019 academic year to increase the excitement and suspense of the competition. The new format includes three unique features: a tournament bracket, trivia competition, and various levels of instrumentation and technology. First, the competition uses a 32-team tournament bracket for all bridges. Bridges are “seeded” into four 8-team brackets based on a combination of previous year’s results and a random number generator. Two bridges are loaded simultaneously on two different load frames by placing 2 lb sandbags in a suspended bucket for each match. At the time of failure for one bridge, the other bridge is unloaded and removed from the load frame; it advances to the next round. This better simulates the repetitive loads that real bridges encounter. This process continues until there are four teams remaining (i.e. the “Final Four”). At that point, the loading procedure returns to the traditional format where each bridge is loaded individually by adding sand to a suspended bucket until complete failure. The four bridges are evaluated and the champion is crowned based on strength:weight ratio and several other factors. Second, a trivia competition was added to address the down time when the bridges are being placed in the load frames. Each team is given an iClicker2 upon check-in to answer questions throughout the competition. The trivia competition includes approximately 30 questions related to civil and structural engineering and one question is revealed between each match along with four multiple choice answers. Teams are given 30 seconds to answer each question. Lastly, various forms of instrumentation and technology were used to enhance the competition. An electronic load cell is used between the bridge and the loading bucket, which allows the supported load to be monitored live during the event and the maximum load on a bridge recorded just prior to failure. The load is also projected on large LED displays for the audience to see. Furthermore, the COVID-19 Pandemic required the competition directors to rethink how to engage an audience remotely. Zoom was used with multiple cameras from different locations that were selectively broadcast into a video stream: a technique that can also be used for in-person competitions. This paper will provide a detailed overview of the competition and its features along with several lessons learned and suggestions for others interested in spicing up their balsa wood bridge competitions.
AU - J Carroll
AU - Kyle Mitchell
CY - Minneapolis, MN
DA - 2022/08/23
PB - ASEE Conferences
TI - How to Spice up Your Balsawood Bridge Competition (Other)
UR - https://peer.asee.org/41146
DO - 10.18260/1-2--41146
ER -