Amplitude attenuation laws of acoustic emission waves in plate structures

Abstract

Although acoustic emission technology has been used in the 
nondestructive testing of various plate structures, its further application and development remain limited because the law of governing erning the amplitude attenuation of acoustic emission waves in 
plate structures remain unclear. This study aimed to reveal the 
amplitude attenuation laws of acoustic emission waves in plate 
structures. Thus, in this study, the traditional model of amplitude 
attenuation, which is in the form of an exponential function, was 
improved in reference to cylindrical waves, and an amplitude 
attenuation model in the form of a power function suitable for 
plate structures was proposed. Moreover, an experimental system 
for the attenuation of acoustic emission waves in aluminum alloy plates was established to experimentally verify the proposed 
model. Finally, the amplitude attenuation laws of acoustic emission waves within the full field, near field, and far field of plate 
structures were discussed. Results show that the amplitude attenuation laws of acoustic emission waves within the full field, near 
field, and far field of plate structures all conform to the power 
function model and gradually reduce as propagation distance increases. In addition, the improved amplitude attenuation model 
better corresponds with the actual amplitude attenuation trend 
within the near-field range of the acoustic emission source than 
other forms of amplitude attenuation models. Specifically, the traditional model of amplitude attenuation model agrees with the 
actual attenuation laws of acoustic emission waves only within 
the far-field range of the acoustic emission source. The results 
of this study provide valuable references for the profound analysis of the propagation characteristics of acoustic emission waves 
in plate structures and can be employed in the research of new 
methods for source localization of burst-type acoustic emission 
waves based on acoustic amplitude attenuation.