Determination of Mechanical Impedance Through Strain Measurement on an Impacted Slender Rod

摘要

An impedance gage based on measurement of strains at two cross sections of a slender rod is studied. The gage rod is in contact with the object at one end and is impacted at the other. The impedance is evaluated from the two strain signals by a two channel fast Fourier transformation analyzer and a desktop computer. Gage prototypes with cylindrical and conical geomtries were tested in the frequency range 50 Hz to 5 kHz for cylindrical objects with known theoretical point impedances. Satisfactory agreement between experimental and theoretical impedances is obtained for both prototypes. The BASIC program used is presented.