Propagation Characteristics of Acoustic Emission Signals in Cylindrical Waveguide Rods

The cylindrical type waveguide rods with five kinds of length and two kinds of diameters had been selected and the broken lead tests had been done on their centre of the end surfaces and the circumferential surface, respectively. And the comparative analysis of the acoustic emission signal amplitude, time-domain waveform and amplitude frequency characteristics throughout the different length and diameter of the waveguide rods had also been dealt with. The results showed that with increase of the waveguide length, acoustic emission signal amplitudes not only from the center of end surface but also from the circumferential surface had attenuation trend, wherein the former was faster than the latter. For the same length of waveguides, the larger the diameter, the lower the acoustic emission signal amplitudes was received; for the same diameter of waveguides, the longer the length, the wider the time-domain waveform graph of acoustic emission signal receiver along a timeline; for the same length but different diameter of the waveguides, the frequency scattering of acoustic emission signals had been shown in the larger diameter of the waveguide rod.