Development of Elasto-Magneto-Electric (EME) Sensor for In-Service Cable Force Monitoring

Stress/force monitoring of in-service steel structures is challenging but crucial to the evaluation of structural safety. A smart elasto-magneto-electric (EME) sensor was recently proposed by the authors for stress monitoring of steel components not only with the superiorities of the traditional elasto-magnetic (EM) sensors such as noncontact monitoring, actual-stress measurement, low cost, corrosion resistance and long expected service-life, but also with higher sensitivity, faster response and higher signal-to-noise ratio (SNR). In this paper, the application of the developed EME sensory system on the cable force monitoring of the Second Jiaojiang Bridge in China is presented. Full-scale experiment, factory calibration and in situ verification for engineering applications were successively carried out, which verify that the EME sensor is feasible and reliable to monitor the in-service cable force as a nondestructive testing (NDT) tool. Long-term on-line monitoring of the cable forces is in progress and the typical monitoring data over 7 months are presented and discussed. It is demonstrated that the proposed EME sensor is feasible for the in-service force monitoring of steel cables and that the EME sensory technology is suitable for developing the stable and reliable long-term monitoring system for steel structures.