June 24, 2017
June 24, 2017
June 28, 2017
The Free-Body Diagram (FBD) is the perhaps the most fundamental concept in all of mechanics and mechanical engineering. It can also be a rather challenging concept to teach, especially to freshmen and sophomore undergraduate students. A simple and intuitive way to teach the concept of the FBD to students is to use the "exploded-view" approach. In this approach, which is inspired by the manner in which the FBDs for trusses, frames and machines are typically treated, the student is asked to separate the body/bodies present in a system from one another and the ground (or any other support) and draw all of the forces/moments acting on each of the individual entities present in the system, including the bodies, ground, supports, etc. Each of these individual entities is drawn and "added" to the other ones and the "sum" of all these components is equivalent to the FBD of the entire system. The advantage of this approach is that the student can account for every force/moment in the system, since there should be an equal and opposite force between any two components that are connected or in contact (Newton's third law of motion), and that the "sum" of all the forces/moments acting on the individual components should be equal to the external forces/moments that are acting on the entire system. After establishing the forces/moments that act on each individual body, the relevant force/moment equilibrium equations can be obtained with two rules of thumb in mind: (1) Ignore the ground and supports and (2) start with the FBD with the least number of unknowns. Two full worked-out examples involving the FBD of particles and rigid bodies will be presented in the final paper along with some preliminary statistics comparing the effectiveness of this approach to other methods of instruction.
Danesh-Yazdi, A. H. (2017, June), The Exploded View: A Simple and Intuitive Approach to Teaching the Free-body Diagram Paper presented at 2017 ASEE Annual Conference & Exposition, Columbus, Ohio. 10.18260/1-2--28968
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: © 2017 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