A Novel Method of Bolt Detection Based on Variational Modal Decomposition

Abstract

The pull test is a destructive detection method, and it can t measure the actual length of the bolt. As such, ultrasonic echo is one of the most important non-destructive testing methods for bolt quality detection. In this paper, the variance modal decomposition method is introduced into the bolt detection signal analysis. Based on the morphological filtering and the VMD method, the VMD combined morphological filtering principle is established into the bolt detection signal analysis method. MF-VMD was used in order to analyze the simulation vibration signal and the actual bolt detection signal. The results showed that the MF-VMD is able to effectively separate the intrinsic mode function, even when under the background of strong interference. Compared with the conventional VMD method, the proposed method is able to remove the noise interference. The intrinsic mode function of the field detection signal can be effectively identified by the reflection of the signal at the bottom of the bolt.