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.