Teaching Design and Strength of Materials via Additive Manufacturing Project-Based Learning

Graduating approximately 150,000 engineering and engineering technology students per year, the engineering education system seeks to teach students to solve problems via analysis and design. Unfortunately, many curricula emphasize analysis at the expense of design, often relegating design activities to cornerstone and capstone design courses and leaving students ill-prepared for substantive capstone projects and post-baccalaureate practice. This work seeks to address this problem by introducing an appropriately-scaffolded design-analyze-build-test spine within an existing Mechanical Engineering Technology second-year Strength of Materials course. The 33-student cohort self-selected into 11 teams of 3 students per team to design, analyze, and additively manufacture 6-inch-long by 1-inch-maximum-width by 1-inch-maximum-height 3D-printed polylactic acid (PLA) beams weighing ≤ 45 grams. Beams were then three-point loaded during a culminating competition. The project intentionally rewarded multiple, competing objectives, including beam mass, maximum force at a 0.050-inch deflection, accuracy of analysis, and creativity. Over 29 calendar days, the project consumed approximately 1.5 in-class hours and was completed using only commonly-available university hardware, e.g., 3D printers and a load frame. Formative and summative surveys were administered to assess student task value, self-efficacy, and opinions. Results indicated that students were primarily motivated by utility and intrinsic task value. Despite 74% of the students having minimal experience with additive manufacturing, 75% of students felt their team had appropriate skills to complete the project. In addition to 84% of students stating the project reinforced their understanding of strength of materials, 95% of students stated that the project increased their understanding of open-ended design and the interconnection between material properties, materials processing, and strength of materials. This work is important in that it demonstrates a case study on how to incorporate design concepts within an engineering analysis course and that analysis and design concepts may coexist within a course. © 2022, Advances in Engineering Education. All Rights Reserved.