Teaching of Beam Deflection Analysis Through Laboratory Experiments

Abstract

Hands-on laboratory skills play a vital role in providing students with a sound understanding of the scientific fundamentals and their application in solving real-life engineering problems. This paper describes a hands-on laboratory project focused on solid mechanics, which is taught as part of a one-semester, junior-level mechanical engineering course titled Core Measurements Laboratory. The project requires students to design, construct and commission an experimental test facility for the characterization of cantilever beam deflection and stress due to pure bending using concomitant methods, consisting of three experimental techniques and analytical predictions. Beam deflection is measured using both a linear displacement transducer (LDT) and digital camera, with corresponding stress measurements derived from strain gage measurements. These measurements are compared with analytical predictions. The project is undertaken over a five-week period by a team of four students. A written project report and oral presentation are conducted on project completion. Emphasis is placed on elaboration of a test plan, sensor installation, data acquisition and LabVIEW programming, as well as analysis of discrepancies between measurements and predictions. The teaching strategy employed to integrate fundamental theory with hands-on experiences is described, with a sample of the measurement results presented. The effectiveness of the laboratory project in enhancing student fundamental and applied knowledge in the subject area, and project management skills, is assessed by monitoring student performance improvements over the duration of the project, as well as through student surveys. On a scale of 1 (deficient) to 4 (exemplary), overall class scores of 2.92, 3.25 and 3.4 were obtained for ABET Criterion 3 Outcomes (b), (d) and (g), respectively, which were assessed using the hands-on project final report and oral presentation. The student survey indicates that student knowledge in fundamentals, sensors, data acquisition and LabVIEW programming improved by 16%, 23%, 30% and 48%, respectively, with the hands on project.