Abstract: Modal frequencies of known good sample parts (SN) are analyzed to determine a pattern which will identify acceptable material and dimensional variations. The data obtained by analysis is then archived. Production parts are then measured at the modal frequencies and the production parts are accepted or rejected after pattern analysis of each part by comparing the production part with response to the pattern identified as acceptable for material and dimensional variations. Production part data is archived for future testing. This procedure is repeated throughout the lifetime of a part, and may be used on parts which are part of an assembly, including other unmeasured parts.

Abstract: Methods for the prediction of the frequency of high order resonant ultrasound spectroscopy (RUS) diagnostic modes are used to limit the band width of diagnostic testing at high order mode frequencies. Testing of parts at low order frequency modes is used to calculate part dimensions, and then these calculated part dimensions are used to predict high order diagnostic mode frequencies. Lower order mode frequencies are used to predict high order diagnostic mode frequencies.

Abstract: A method for temperature compensation of resonant frequency measurements of parts uses Temperature Functions which are mathematical relationships between measured resonant frequencies and temperature. The Temperature Function is used to adjust frequencies measured at any temperature to a resonant frequency at a pre-determined reference temperature. The temperature of a surrogate part or specimen can be measured to eliminate the need to touch a part being tested where the surrogate part has essentially the same dimensions and material properties and is positioned and mounted such that its temperature is essentially the same as the part being tested. The temperature function may be in the form off.sub.r =f.sub.m *(1+(T.sub.m -T.sub.r)/C)where f.sub.r is the resonant frequency compensated to the reference temperature, f.sub.m is the measured resonant frequency, T.sub.m is the measured temperature and T.sub.r is the reference temperature.

Abstract: A part undergoing resonant ultrasound testing is simultaneously driven at a plurality of resonant test frequencies. The response of the part is measured simultaneously. There may be one or more driving transducers and one or more vibration sensing transducers.

Abstract: Methods for the prediction of the frequency of high order resonant ultrasound spectroscopy (RUS) diagnostic modes are used to limit the band width of diagnostic testing at high order mode frequencies. Testing of parts at low order frequency modes is used to calculate part dimensions, and then these calculated part dimensions are used to predict high order diagnostic mode frequencies. Lower order mode frequencies are used to predict high order diagnostic mode frequencies.