Virtual On line
June 22, 2020
June 22, 2020
June 26, 2021
Engineers are often faced with the task of answering questions about physical systems that are either being designed or already in use. However, many “real-life” problems encountered by engineers have no set procedure for finding the answer, causing the engineering to rely on intuition, creativity, and knowledge of physical systems to determine an appropriate evaluation procedure for each system. This situation requires the engineer to have the ability to design, fabricate, and evaluate an appropriate testing apparatus. However, many engineering curricula do not produce engineers with the skillset needed to develop this sort of apparatus. This paper introduces a systematic way of developing these key prototyping skills in engineers through an open-ended mechanics of materials project that challenges students to create a means for evaluating different physical systems. This project requires students to pull knowledge from coursework in several areas including civil engineering, mechanics of materials, basic circuits and controls, and communication. Throughout the term, students in a sophomore-level mechanics of materials course build a tensile testing machine with a frame made of aluminum extrusions with a lead screw driven by a stepper motor. The motor is controlled using a microcontroller that the students program to respond to various inputs such as buttons or readings from a load cell. The final assembly also requires students to design, model, and 3D print certain parts. The first project assignment of the term has students measure motor torque at various speeds. This reinforces statics concepts such as solving for an unknown torque in a three-dimensional system in static equilibrium. The second assignment studies stress and strain properties of various materials by using the tensile tester. Both tensile and column buckling properties are observed in this way. The final assignment has students utilize their knowledge of material strength gained from the second assignment to design and build a small planar truss. Each truss is then evaluated using the tensile testing apparatus. By using cheaper materials and a testing apparatus the students can take with them outside of class, the students are able to test preliminary prototypes. This allows students to build their understanding of static systems as well as develop effective engineering design skills through trial and error. The effectiveness of this project is evaluated by comparing students in control and experiment sections of the course. The students in the control course carry out projects similar to the second and third project assignments, but without the testing apparatus made by the students. The students are evaluated using concept inventories for both statics and physics. Student feedback on the perceived effectiveness of the project is also collected through surveys that include both Likert-scale questions and open-ended questions.
Hilton, E. (2020, June), Work in Progress: Developing Mechanics of Materials Skills through an Integrated Prototyping Project Paper presented at 2020 ASEE Virtual Annual Conference Content Access, Virtual On line . 10.18260/1-2--35590
ASEE holds the copyright on this document. It may be read by the public free of charge. Authors may archive their work on personal websites or in institutional repositories with the following citation: © 2020 American Society for Engineering Education. Other scholars may excerpt or quote from these materials with the same citation. When excerpting or quoting from Conference Proceedings, authors should, in addition to noting the ASEE copyright, list all the original authors and their institutions and name the host city of the conference. - Last updated April 1, 2015