Monitoring of Bolt Looseness-Induced Damage in Steel Truss Arch Structure Using Piezoceramic Transducers

In this paper, we develop a stress wave-based active-sensing approach using piezoceramic transducers to detect the bolt looseness-induced damage in steel truss arch structures. A specimen of a steel tress arch structure was designed and fabricated. The structure consisted of top chords, bottom chords, Web members, and gusset plates, which were all connected by bolted connections. To implement the active sensing approach, the lead zirconate titanate (PZT) transducer bonded on the gusset plate was used as an actuator to generate stress waves, and the PZT transducers mounted on the other parts, such as top chords, bottom chords, and Web members, were used as sensors to detect the propagated stress waves. Based on the tightness of the bolts, the specimen had three different states: the healthy state, damage state I, and damage state II. The signals received by the PZT sensors were analyzed using the wavelet packet analysis. In addition, the structure stiffness was also considered as a comparative approach in this paper. The experimental results illustrate that when the initial looseness-induced damage occurs, the structure stiffness is not significantly reduced while the wavelet packet energy changes significantly, revealing the advantage of the proposed approach over the stiffness-based method. These research results demonstrated that the developed piezoceramic-based active-sensing approach has potentials to identify the initial bolt looseness occurrence for steel truss arch structures.