Structural Verification Using Modal Frequency Testing: A Nondestructive Evaluation.

摘要

An investigation was carried out to study the application of modal frequency testing as a nondestructive method for structural verification and bond characterization of a dissimilar-metal structure joined by solid-state bonding. Important to the success of this investigation were the contributions from three disciplines: nondestructive evaluation, experimental modal analysis, and statistical analysis. This interdisciplinary effort resulted in a unique concept of structural verification-the use of modal frequency testing to determine the geometrical consistency of precision parts and to characterize the condition of the silver solid-state bonds in a beryllium/stainless steel structure during its manufacture. Two methods of data analysis will be presented: one is an overlay of frequency response measurements to observe macro effects, and the other is principal component analysis of modal parameters to distinguish micro effects. The sensitivity of modal testing to small changes in the mass of a structure will also be discussed. 12 refs., 23 figs. (ERA citation 14:008726)