MEASUREMENT AND MONITORING OF MECHANICAL LOADS OF LARGE SLENDER STRUCTURES USING DISTRIBUTED FIBER OPTIC SENSOR

A method for measurement and monitoring of mechanical loads in large slender structures is presented based on continuous strain data obtained from distributed fiber optic sensor. An experimental study was carried out on an aluminum cantilever beam. A static load test was performed and the calculated moment based on the measured strain from the distributed fiber optic sensor agrees well with the actual applied moment. A series of damages was inflicted on the beam, and free vibration tests were carried out for each damage case. The estimated natural frequencies using the dynamic strain measured by the distributed fiber optic sensor for each damage case are found to compare well with those from a conventional accelerometer and a numerical analysis based on an energy method.