Integrating a 3-D Printer and a Truss Optimization Project in Statics

There is a need to integrate hands-on engineering analysis and design problems and exciting build technology in lower division engineering courses to stimulate interest and increase students’ capacity to solve divergent, open-ended based problems. In this evidence-based practice paper, we discuss the development, execution, and impact of a truss optimization project given to students in Statics. The students were required to optimize two different polyactic acid (PLA) 3D printed trusses using compression and tensile mechanical strength properties. The students were required to provide the optimal tension and compression member cross-section to be 3D printed, provide a three-dimensional drawing using a user-friendly open source CAD software, and provide a summary of the results in a poster presentation. The optimal truss design was then printed, assembled, and tested in the classroom and the results were compared to the engineering design solutions. Students perception of their ability to interpret and analyze data, organize presentations, solve engineering problems, tinker, engineer, and design was assessed using a 21 item online survey. The survey items were taken from both validated instruments and the ABET Criteria 3 course outcomes: a, b, and e. Survey data was collected from the test population (students given the project) and compared to a control population (students not given the project) to assess the impact of the project on engineering self-efficacy. The results indicate there is a statistically significant gain in student engineering skills self-efficacy, student perception of their ability to analyze and interpret data, ability to solve engineering problems, and organize a presentation.