Attenuation of Ultrasonic Guided Wave on Buried Illumination Pillar

Abstract

This paper aims the development of a nondestructive inspection system for illumination pillars. The system detects the corrosion of a pillar by a screening inspection with a guided wave. Corrosion mainly occurs in the root part of the pillar in the ground. Small corrosion scatters and attenuates the guided wave. The soil around the root part of the pillar also attenuates the guided wave. Accurate detection of the corrosion needs to estimate the attenuation of the guided wave by the soil. This paper derives an attenuation variable from a model of a pillar partially buried in the soil. Experiments using electromagnetic acoustic transducers demonstrate guided wave propagation. We verify the attenuation variable of T(0,1) and L(0,2) modes from the experimental data.