Detection Method for Bolt Loosening and Washer Damage in Flange Assembly Structures Based on Phased Array Ultrasonics

Abstract

ABSTRACT During the service life of flange assembly components, factors such as corrosion and vibration can lead to washer damage and loosening of fastening bolts, resulting in fluid leakage. Traditional inspection methods are not applicable for assessing the extent of washer damage and bolt loosening due to the non-dismantlable nature of flanges and the challenges posed by the working environment. To address these issues, this paper proposes a detection method utilizing phased array ultrasonic testing (PAUT). By analyzing the peak and side-lobe states of reflected signals, the extent of washer damage can be determined. A mathematical relationship is established between the depth of washer defects and the peak reflection amplitude, enabling the assessment of washer damage in flange structures. This method facilitates the measurement of the positions of washer damage and bolt loosening in flange structures, providing technical support for practical industrial applications.