Acoustics Laboratory Exercises at GMI

The following laboratory exercises have been developed for use with a senior level course in Acoustics, Noise, and Vibration, (course number ME-530 / PHYS-580) at GMI Engineering & Management Institute. The links below will take you to HTML versions of the laboratory exercises, each complete with theoretical background, procedure, analysis, and some sample measurements. The lab exercises are also available for downloading as PostScript files.

Labs 6 and 8 are still being formatted for HTML: equations and figures need to be converted from TEX code to a format readable by most Web browsers.

1. Introduction to Sound Waves
2. Measuring the Directivity of a Loudspeaker with and without a Baffle
3. Introduction to Frequency Analyzers
4. Sound Power and Vector Sound Intensity
5. Absorption Coefficients and Impedance
6. Room Acoustics and Reverberation Time
7. Acoustic High-Pass, Low-Pass, and Band-Stop Filters
8. Computational and Experimental Modal Analysis of a Clamped-Free Bar

If you have problems downloading any of the files contact: drussell@nova.gmi.edu

Number of visitors since counter was reset May 7, 1997:

Revised: March 6, 1997

Copyright © 1996 Daniel A. Russell, Science and Mathematics Department, GMI Engineering & Management Institute

Papers describing these laboratory exercises

Two papers, which discuss the eight laboratory exercises and their usefulness in acoustics education, were presented at 1996 Annual Conference & Exposition of the American Society for Engineering Eduation (ASEE), (Washington DC, June 23-26, 1996).

" Laboratory Instruction in Acoustics and Vibration," T. Cameron, D. Russell --- Session 2526

Eight laboratory exercises have been developed for a senior-level course in Acoustics, Noise and Vibration to introduce students to sound and vibration engineering. Laboratory topics include wave propagation in fluids and solids, acoustic and mechanical impedance, and signal processing. The laboratory exercises demonstrate governing physical principles, provide experience using state-of-the-art tools and techniques in sound and vibration engineering, and introduce applications in architectural acoustics and noise and vibration control. The laboratory exercises are sequenced to facilitate comprehension, with each successive exercise building on concepts demonstrated previously. In this paper we describe the laboratory exercises, explain the objectives and learning outcomes expected of each exercise, and discuss how the sequence of exercises enhances comprehension.

" Coupling Simulation and Experiment in Noise and Vibration Engineering," T. Cameron, D. Russell --- Session 3226

Computer simulation and experimental testing play major roles in noise and vibration engineering. Modal analysis of structures, for instance, is regularly performed experimentally and with finite element analysis. Often the integration of simulations and experiments consists of nothing more than adjusting a fudge factor, like a material property, to get simulations to agree with test results. However, the current emphasis in industry and research laboratories is to more tightly couple testing and simulation---using test results to validate simulation models and simulation results to design experiments. For example, finite element analysis is used to identify how best to support and excite a structure to produce a particular vibration, and modal test results are used to establish "modal assurance criteria" on finite element simulations.

This paper presents two laboratory exercises that demonstrate the importance of coupling computer simulations with experiments for mutual validation. The exercises from a new course in "Acoustics, Noise and Vibration" at GMI Engineering & Management Institute also introduce students to tools and practices used extensively in noise and vibration engineering. The other six experiments in the course, like most undergraduate laboratory experiments, focus on demonstrating physical principles. These two exercises focus on the tools and methods employed in noise and vibration engineering. The first exercise comes near the beginning of the course and deals with the frequency domain analysis of signals using fast Fourier transforms (FFTs). The second exercise, near the end of the course, deals with structural modal analysis.