Understanding additive manufacturing part performance through modeling and laboratory experiments

Abstract

Additive manufacturing (AM) has attracted extensive attention in recent years due to its wide applications in academia and industry. As most of the AM parts are built layer by layer, it is clear that parts manufactured from AM processes would perform differently compared to parts manufactured from conventional processes such as casting and injection molding. Since students often rely on AM for part fabrication in courses and capstone projects, and industries could adopt AM to produce components for their products, there is a need for students to understand the mechanical performance of parts manufactured from AM processes. As such, an AM laboratory exercise, with a focus on experiential learning on the behavior of different materials, is introduced. This paper presents an effort of developing and implementing laboratory materials for students to conduct experiments with AM parts and to understand the anisotropic nature of the material. In this development effort, tensile specimens of Acrylonitrile Butadiene Styrene (ABS) are printed using Fused Deposition Modeling (FDM), one of the most popular AM technologies, from three different building configurations. In the first lab, students are assigned to characterize the tensile behavior of the specimens. The test results are then compared to the bulk ABS property. In the follow-up labs, the constitutive model of AM ABS, adopted from a graduate research project, is presented to students. New parts including a beam and an L wrench which also fabricated using FDM are then tested under three-point-bending and combined bending and torsion test, respectively. Students are instructed to compare the performance of the AM parts to that of the parts with bulk ABS property. Student feedback of the learning experience is summarized. From surveys, it was found that the laboratory exercises can enhance students' understanding of AM part performance. The developed materials can be adopted by others teaching in engineering technology programs.