Feasibility study of detecting the end contacting status of threaded-sleeve-connected reinforcing bar using magnetostrictive guided wave

Abstract

The reinforcing bar connected by threaded sleeve is widely used. The end contacting status under the sleeve indicates the tightness of the threaded sleeve connection. In this paper, the feasibility of using magnetostrictive guided wave to detect the end contacting status of the reinforcing bar is studied. Firstly, the propagation characteristic of the wave propagating through the threaded sleeve connection is analyzed. The end contacting status affects the reflection and transmission of the wave. Then, experiments are carried out on a thread-sleeve-connected reinforcing bar. The passing signals of the threaded sleeve connection at an exciting frequency of 30 kHz can be used to distinguish end contacting status of the reinforcing bar. Additionally, the peak voltage of the passing signal’s first passing wave decreases with the increasing loosening angle of the threaded sleeve connection. The study proves the feasibility of detecting the end contacting status using magnetostrictive guided wave.