KEENzine4

THAT’S ENGINEERING UNLEASHED! YOU STUDENTS + + CONNECT ACCESS RESOURCES AND CURRICULUM ATTEND EVENTS, TRAININGS, AND SEMINARS COLLABORATE ACROSS DISCIPLINES & INSTITUTIONS JOIN THE MOVEMENT AT E NGINEERING U NLEASHED.COM are simplified using boundary conditions. To solve for nodal displacements, students compute: U G = [K G ] -1 * F G , where K G is the global stiffness matrix and F G is the force matrix. They consider not only each force of the attached members, but also the weight of the structure itself. They make decisions to balance cost, weight, and safety. In order to prove the structure is safe, teams use displacement information to calculate stress along the length of the tree trunk. They compute the derivative of displacement along the trunk using du—dx . In turn, they compute stress: , where e is strain. In class, groups discuss their progress. Teams compare the maximum desired stress in their designs, . They use a safety factor to ensure internal loads do not exceed maximum buckling loads. For the final assignment, teams submit a report on their treehouse design and trunk analysis. The goal is to demonstrate that their treehouse is the best in class. They prove it is safe with their computational tool and justify their design decisions. One team mentioned they chose their treehouse height based on the average height of the tree line in the Poconos. While Aunt Ada wants to be able to see the fireworks, she shouldn’t be towering above the forest. Some teams designed a smaller, more intimate space at the top for nighttime viewing and more spacious quarters within the trunk for entertaining and living. Other teams put spacious structures at the top to achieve “a grand visual command for all visitors to Aunt Ada’s playful abode.” The KEEN objectives of curiosity, connections, and creating value are worked into the course without sacri- ficing any technical material. Students are motivated to be curious as they are presented with limited information and asked to solve a complex problem. They also make con- nections to how their algorithms can be used for accuracy and safety. In their final report, I ask questions including: What sparked your curiosity and why? If you explored something, what was it? How did it help Aunt Ada with her needs, and to what else might it be connected? Some teams looked at the environment and connected their treehouse design to sustainability goals. Other teams focused on optimization and presented utilitarian designs with compelling evidence for their safety. One student wrote, “I found it especially mind-blowing how inputting strings of numbers and characters into a computer could tell me whether my proposed structure would fail with the complex loading conditions.” As the professor, I saw numerous examples of measurable moments. Watching one team compute a rough estimate cost of their proposed titanium tree trunk, and realize the comparison cost of using steel, convinced me that my course revisions are helping my students understand strength of materials in many ways! Before the change, my students were frustrated. When they learned the finite element computer algorithms, there was no context. Prior to this injection of entrepreneurially minded learning, one student said, “I felt like I learned little except how to be frustrated over a computer code.” In response to the altered project, one student stated, “Specifically, after discussing 1-D finite element analysis in class and completing a few homework problems, I thought that it was awesome that I use the same techniques to write a program to analyze stress in a real-world loading scenario!” This sentiment, or something similar, was expressed by a surprising number of students. Adding elements of the entrepreneurial mindset is critical to student learning. They learn faster and are more interested. I believe that this is not only because of the improved context, but also the ownership that comes with an emphasis on curiosity and creating value. One student summed it up well, “I can talk to you about beam bending and finite element analysis all day, but if you asked me how I would take those skills and turn them into a self-oriented business that is profitable, it would be tough to answer. It is projects like these that expose us to how our skillset can be used in the professional world, and that is everything to a student entering the job market. I truly wish that all of my professors took this approach to teaching.” In the writing of this article, Professor Webb collaborated with Deanna Kocher, a rising senior pursuing an integrated degree in engineering, arts, and sciences at Lehigh Uni- versity. She aspires toward a career in toy design by combining mechanical engineering, design, and psychology. 6 7