Accession Number : AD0634745
Title : FOURIER-TRANSFORM TECHNIQUE FOR MEASURING TERMINATING IMPEDANCES.
Descriptive Note : Technical rept.,
Corporate Author : MINNESOTA UNIV MINNEAPOLIS DEPT OF AERONAUTICS AND ENGINEERING MECHANICS
Personal Author(s) : Plunkett, R. ; Wittig,L. E.
Report Date : 1964
Pagination or Media Count : 27
Abstract : The mechanical impedance of a foundation depends, in part, on the characteristics of the column attached to it. For this reason it is important to have a technique to find that mechanical impedance with the column in place; this requirement rules out direct measurement with an impedance head. This study was made to determine the usefulness of a transient loading technique for measuring the mechanical impedance of a complex termination. The method determines the impedance at the end of an elastic bar from the Fourier Transforms of pulse shapes in the bar. Experimental results for a simple termination show that this technique can be used to measure the impedance of a lumped parameter system. However, comparison between transient loading measurements and direct measurements with an impedance head for a more complex termination show that not enough frequency information can be obtained to determine its impedance accurately enough. (Author)
Descriptors : (*RODS, VIBRATION), (*INTEGRAL TRANSFORMS, MEASUREMENT), LOADS(FORCES), SHEAR STRESSES, STRAIN(MECHANICS), FREQUENCY, ELASTIC PROPERTIES, MECHANICAL WAVES
Subject Categories : Mechanics
Distribution Statement : APPROVED FOR PUBLIC RELEASE