Seeing Structures: Interactive CAD Models in Mechanics of Materials

Abstract

When COVID-19 necessitated remote teaching, mechanics faculty needed to quickly convert hands-on teaching props into equally effective online equivalents. This constraint sparked a new innovation in a Mechanics of Materials course. Unable to pass around a foam beam to demonstrate concepts such as "plane sections remain plane," or an annotated wood cube to illustrate the sign convention for shear stress, dozens of interactive CAD models were developed with the open-source browser software SketchUp. The CAD models have been uploaded to SketchUp's 3D Warehouse and placed in the public domain. They are opened by students in browser windows and are manipulated in 3D space. Familiarity with the modeling software led to a second innovation: the presentation of exam problems in SketchUp. In an exam, students are provided with a hyperlink to a CAD model in the public domain. Students navigate the model in 3D space, note key dimensions, and perform requested calculations. Assessment of the impact of these innovations is ongoing in Fall 2020, as the 2D problems used on paper exams in prior years are now being presented to students in full 3D. This paper will explain how this approach is easily accessible to all faculty, including those with minimal CAD experience. Additionally, the public-domain 3D models will be demonstrated, and links shared, so that these visualizations may be used at other institutions and shared across the engineering education community.