PULSE LENGTH AND FREQUENCY SPECTRUM OF REAL AND SIMULATED ACOUSTIC EMISSION SIGNALS.
Abstract
The paper reports on a study in which the effect of the transducer on the waveform of acoustic signals was investigated. Pulse length and frequency spectrum of real and simulated signals were obtained as a function of distance from the source to the receiving transducer. Artificial sources were investigated. The signals used are obtained from brittle fracture of a graphite thin tube or from using a commercial pulser. A narrow band transducer is used as well as a broad band in the range from 0. 1 to 2 MHz. The waveform is explained in terms of different wave propagation modes which affect the rise and decay times of the transducer.