The Fiber Bragg Grating Sensor and its Interrogator for Dynamic Strain Measurement of Concrete

The fiber Bragg grating (FBG) sensor is the most appropriate to measure strain of concrete. Employing a specifically designed FRP package, a FBG sensor for concrete dynamic strain measurement was designed. To interrogate the dynamic response of the FBG sensor, the corresponding interrogator was developed by using a novel reflect wavelength measurement method. A series of tests such as measuring dynamic strain of concrete specimens impacted with drop hammer and split Hopkinson pressure bar (SHPB) were conducted. The results show that the sensor and its interrogator respond rapidly to impact and have a stable performance. The system can be used for a real-time and rapid dynamic strain measurement in concrete dynamic performance tests or weapons effects tests.