A new method for analysing dispersed bar gauge data

Abstract

A new method is developed for analysing dispersed stress (or strain) signals from a Hopkinson bar. In this method the incident signal is written as a rectangular-windowed Fourier series. It treats dispersion by accounting for both the time-of-arrival of the various frequencies and the associated phase shifts in a dispersed signal. An analysis of a shock wave generated by a sphere of high explosives in a water tank shows that this method gives better resolved peaks than the existing FFT method, for signals from blast waves. It also gives an indication of when components exist in the signal that are not due to dispersive propagation.