2025 ASEE Annual Conference & Exposition

Note: this abstract is being submitted for the Activities with Impact! special session

Introductory materials engineering courses are often a student’s first exposure to the fundamental engineering science concepts of stress and strain, as well as key material properties such as elastic modulus and yield strength. Often these concepts are introduced in a formal, abstract way, despite longstanding research that shows improved learning gains through discovery-based approaches. Here, we present an experiential approach to introducing these concepts to students in a Materials Engineering course that is part of the core curriculum within a general engineering program at a small liberal arts college. In the exercise, student groups are provided with an elastomeric strip to use as a baseline for comparison, and several variations on the strip which are identical in all ways but one – the variants are thinner or thicker, longer or shorter, wider or skinnier, or are composed of an elastomer with a different elastic modulus. By qualitatively comparing the estimated force required to deform each strip, students discover that it is influenced by both geometry and material composition. The problem this presents is made apparent when students are provided with an unknown elastomer and asked to predict if it is the same material as the original strip. At this point, the instructor guides the class toward the concepts of stress and strain, which account for geometric factors, and shows that the ratio of these values (the elastic modulus) is characteristic of a material. This activity is also used to introduce the concept of a tensile test for characterizing materials, and a similar follow-up activity with polyethylene strips is used to introduce the concepts of yield, necking, and fracture.