9411387 Feng Experimental research of new optical fiber sensors for monitoring civil infrastructure systems is planned. Optical sensors employ a vibrating wire whose tension can be modulated by external force, strain, or vibration and is translated into the change in the wire vibration frequency. The wire vibration frequency is detected by light sent to and reflected from the wire through an optical fiber cable. Compared to other existing optical fiber sensors which tend to suffer from the lack of reliability and robustness, the sensors have two significant advantages: one is that the sensing head is a vibrating wire (rather than an optical fiber), which can sense a specific physical quantity without interference from miscellaneous effects: the other is that the wire vibration is a well understood physical phenomenon. In fact, with a high level of reliability, its frequency is optically measured and transmitted to recording and other devices through the optical fiber without attenuation or distortion. These advantages should make the sensor system simple, reliable and robust, and hence more readily deployable in civil infrastructure applications.
