Reusable Passive Wireless RFID Sensor for Strain Measurement on Metals

A reusable passive radio frequency identification (RFID) sensor is reported for wireless strain measurement on metals. The characteristics of the proposed sensor are assessed on aluminum tensile specimens. The received signal strength intensity (RSSI) from the RFID sensor and the frequency corresponding to the maximum RSSI are used to measure the specimen strain. Besides strain, the yield, ultimate tensile strength and failure points of the specimen could also be identified from the RSSI measurements and correlated with strain gauge load cell data. Digital image correlation measurements gathered during tensile tests confirm that the sensor does not deform during tensile loading and is reusable.