A NOVEL ADDITIONAL STRUCTURE WITH POWER LAW THICKNESS FOR ACOUSTIC EMISSION SIGNAL ENHANCEMENT OF WEAK DAMAGE IN PIPELINE

As a passive monitoring technology, acoustic emission (AE) technology is widely used to monitor pipeline leakage, corrosion, and other damage. However, the AE signals detected by sensors in the pipeline structure are sometimes exceedingly faint due to signal attenuation. Concurrently, under the influence of background noise, the setting of the threshold voltage can easily result in the omission of AE events, compromising the effective monitoring of subtle pipeline structural damages. Therefore, an additional structure with power law thickness was proposed to enhance AE signal. Firstly, the finite element method was used to verify the enhancement effect of the proposed additional structure on the AE signal. Secondly, the propagation characteristic of AE waves in the proposed additional structure was studied, and the effect regulations of typical structural parameters such as the sensor coupling thickness, index, and additional structure height on the signal enhancement effect were given. Finally, an additional structure suitable for pipelines was proposed, and the enhancement performance of AE signals was studied. The results show that the proposed additional structure can effectively boost the amplitude of AE signal and has a good potential for application in pipeline weak damage signal picking and damage early warning.