Two extensions of the shock spectrum technique are developed for use in pulse signature analysis. A shock spectrum ratio is proposed and compared to the Fourier transfer function for the detection of small perturbations on a larger pulse shape. The shock spectrum ratio is shown to have good sensitivity to the relative size of the perturbation. The shock spectrum ratio approach is extended to a new type of spectrum named “slot transform.” This specialized transform is shown to have several advantages with respect to the Fourier transform in the development of magnitude transfer functions. The transform was developed for analysis of digitized acoustic emission pulses where a rectangular time window is preferred. These two extensions of shock spectrum methods are tested on experimental data from high g shock tests and acoustic emission measurements from damaged and undamaged ball bearings. Deconvolution of the acoustic emission data was necessary before the shork spectrum, ratio was capable of indicating the relative damage of the bearings.

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