Asee peer logo

Construction of a Vibrating Structure for Demonstration of Vibration Measurement and FFT Analysis

Download Paper |

Conference

2014 ASEE Annual Conference & Exposition

Location

Indianapolis, Indiana

Publication Date

June 15, 2014

Start Date

June 15, 2014

End Date

June 18, 2014

ISSN

2153-5965

Conference Session

New Course Development Concepts in ET II

Tagged Division

Engineering Technology

Page Count

10

Page Numbers

24.317.1 - 24.317.10

DOI

10.18260/1-2--20208

Permanent URL

https://peer.asee.org/20208

Download Count

441

Request a correction

Paper Authors

biography

Aaron Alexander Oklahoma State University Orcid 16x16 orcid.org/0000-0001-7254-3619

visit author page

Aaron Alexander is an Assistant Professor in the Department of Mechanical Engineering Technology at Oklahoma State University. He received is BSE from Messiah College and his MSME from Purdue University. Before entering academia he spent eleven years as an Acoustical/Noise Control Engineer in industry and still continues to consult in that field. His research interests are fluid flow, wind turbines, noise control, and computational fluid dynamics.

visit author page

author page

Kenneth Belanus Oklahoma State University

Download Paper |

Abstract

Construction of a Vibrating Structure for Demonstration of Vibration Measurement and FFT AnalysisAbstract:Many Mechanical Engineering Technology (MET) programs include a Basic Instrumentationclass structured to give students hands-on experiences with measurement and analysis systems.As part of a module on vibrations and the Fast Fourier Transform (FFT), a lab was developed tocreate a three-tiered vibrating structure. This test apparatus consists of relatively inexpensivecomponents with threaded rods for the columns, plywood for the tiers, and an adjustable orbitalsander for the vibration source. The vibration source is mounted to the top tier, and its rotationalspeed is adjusted by a controller made for common power tools.Different vibrational modes for the structure can be observed by varying the speed of thevibration source. In one mode the entire structure sways back-and-forth with the top tier showingthe largest displacement. In a second mode the center tier is vibrating while the upper and lowertiers remain nearly motionless.One or more accelerometers may be attached to the tier having the largest displacement for aspecific mode. The accelerometer output is measured using either an oscilloscope or a computerdata acquisition system (DAS). A second test may be performed using a weight on the centertier to demonstrate a change in natural frequency with the added mass to the system. It is alsopossible to adjust the natural frequency by adjusting the position of the center tier relative to theupper and lower tiers.Including the oscilloscope in the required measurements gives the student exposure to a secondmeasurement system as well as allowing them to double-check the results of their analysis of thedata from the DAS. Analysis of the data is performed outside of the lab using MathCAD orExcel and builds off a previous tutorial lab on frequency analysis methods based on Fast FourierTransform (FFT) methods. The students are required to use the FFT results to identify theresonant frequencies as part of their lab report

Alexander, A., & Belanus, K. (2014, June), Construction of a Vibrating Structure for Demonstration of Vibration Measurement and FFT Analysis Paper presented at 2014 ASEE Annual Conference & Exposition, Indianapolis, Indiana. 10.18260/1-2--20208

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: © 2014 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