声发射信号在圆柱型波导杆中的传播特性

Propagation Characteristics of Acoustic Emission Signals in Cylindrical Waveguide Rods

选用5种长度、两种直径的圆柱型波导杆,分别在其端面圆心、圆周表面上进行断铅试验。并对比分析了不同长度、直径的波导杆对接收声发射(AE)信号的幅度、时域波形、幅频特性产生的影响。结果表明:随着波导杆长度的增加,端面圆心、圆周表面上声发射信号的幅度都有衰减趋势。其中,端面圆心处的声发射信号幅度较圆周表面上的衰减大。相同长度的波导杆,直径越大,接收到声发射信号的幅度越小;而相同直径的波导杆,长度较长接收声发射信号的时域波形图在时间轴上伸展较宽;相同长度、不同直径的波导杆,直径大的对声发射信号有频散作用。

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.