Health Monitoring of Bolted Spherical Joint Connection Based on Active Sensing Technique Using Piezoceramic Transducers.

摘要: Bolted spherical joints are widely used to form space steel structures. The stiffness and load capacity of the structures affected by looseness bolted joint connections in connections, which can be caused fabrication error, low modeling accuracy, "false twist" installation process, may negatively impact structure even lead severe accidents. Furthermore, it is difficult detect connection from outside since bolts connect spheres with rods together inside. Active sensing methods proposed this paper monitor tightness status using piezoceramic transducers. A triangle-on-triangle offset grid composed tube bars was fabricated as specimen validate active methods. Lead Zirconate Titanate (PZT) patches were sensors actuators status. One PZT patch mounted on central sphere at upper chord an actuator generate a stress wave. Another bar sensor propagated waves through connection. energy wave wavelet packet analysis time reversal (TR) method quantify transmitted signal between detected. In order verify effectiveness, repeatability, consistency methods, experiments repeated six times different positions. experimental results showed that TR effective detecting connections. monitoring transducers levels efficiently shows its potential guarantee safety construction service.