Abstract:
The present thesis covers the pioneering effort of establishing an infrastructure for conducting research into the analysis of
Acoustic Emission signatures, with emphasis being placed upon the
recovery of the true surface waveform for a given transient input.
The topics covered in this work are:
The p·rovi s ion of the necessary computer software for the handling
and processing of the data. Here, a method is included for the
correction of phase errors introduced by the sampling/multiplexing of
·the signals, which provides the basis for the implementation of data
convolution.techniques in the frequency domain.
J°he development of an experimental rig and source of excitation,
later applied to the design of transducers.
The development of a new transducer configuration, capable of
producing a relatively flat frequency response (±7dB) over the
frequency range 300 KHz - 2 MHz.
The development of a procedure for the calibration of transducers,
based upon a modified reciprocity method. The technique produces
the calibration of transducers in relative terms, requiring a comple- . .
mentary method to provide the reference level for the calibration.
As a means of assessing the proposed techniques, the
transducer calibration was applied to the de-convolution of pulses
generated with a step forcing function, and the results compared with
an equivalent theoretical model previously published.