The sound wave in a cylindrical steel bar, generated by a light tap on one of its ends, is recorded by a microphone located near the other end. A sound analysis software is used to obtain the resonance spectrum of the bar. Longitudinal and flexural vibration frequencies are obtained from the peaks of the spectrum. The speed of sound, Young’s modulus, and Poisson’s ratio of steel are obtained.
REFERENCES
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Many software programs for recording and editing sounds can be found on the World Wide Web. In this work, we have used the freeware AUDACITY 1.2.6 for Windows (http://audacity.sourceforge.net/).
13.
The speed of sound in a solid depends on several factors such as its composition and the method of production. Thus, one can find in the literature different values for the speed of sound in steel. For example, one finds a value of 5130 m/s in
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By applying the hit with the hammer perpendicularly to the axis of the bar, at a point on the lateral surface close to one end (lateral hit), one can measure 21 flexural frequencies.
18.
Reference 6, p.
526
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