Virtual Hands-on: Taking a Design Lab Online

For engineering design curricula, the COVID-19 pandemic introduced an interesting design challenge of its own. How do we run normally hands-on, data-driven labs on-line that emulate the experience of a turnkey design project that produces a physical prototype? "Structural Performance and Failure" is a required team-based sophomore design class at our university. The project topic is the design, fabrication, testing, and analysis of trusses. The pedagogical context is the application of theory informed by data to solve a defined problem through an iterative design process. Tension, compression, and shear are introduced in the context of truss theory. Theoretical calculations and published specifications are juxtaposed to data collected from testing brass profile and assembly samples toward the understanding of how geometry and loads interact. Truss geometries are then analyzed mathematically to calculate theoretical failure loads and modes. The final design project involves choosing base geometries and iterating them toward a chosen design goal guided by an understanding of the data-attenuated theory. Groups choose one truss design to fabricate and test, allowing a comparison of theoretical and empirical failure results. When analyzing this course to go on-line, we realized that students do only two things hands-on in the lab: data collection and prototype fabrication. We can supply data and prototype testing gleans only two datapoints: truss failure load and weight. If we remove these two curriculum components, the bulk of the work and learning outcomes remain intact: a complex, creative thought process linking theory and data that is quantified and expressed through Excel. This realization led to more detailed explorations in Excel, adjusting the assignments to go deeper into calculation and display capabilities. Tension, compression, and shear theory are compared to material and profile data in a series of detailed investigations that require careful calculation sequences linked to clear display graphics. In addition, assignments are presented as real-world design exercises requiring Excel modelers that allow for quick input adjustment to produce automated design outputs. In the final project, the design process is similar to the in-class curriculum with truss geometries analyzed and iterated, but a "theoretical-empirical" truss design is conceived to replace fabrication. This design adds the physical dimensions and strength analysis of joints and uses empirical data rather than theoretical calculations to estimate truss member strength and weight. This approach allows a comparison between simple planar truss geometry and actual physical dimensions of a "theoretical-empirical" truss that could be fabricated, thus maintaining the theory to practice comparison of the hands-on course. Project data is quantified and clearly displayed through a nuanced interlinked automated multi-page Excel modeler. What the on-line course looses in hands-on lab experience, it gains in a more robust investigation of the interplay between data and theory, a deeper dive into Excel as a design resource, and a very specific demand that teams display their understanding of theory as applied to an iterative design process. This paper describes the specifics of how this was accomplished and the preliminary results gleaned from two semesters of running the course on-line.