Crack Propagation Monitoring of DCB Composite Specimens Using Distributed Optical Fiber Sensor

Abstract

In the conventional DCB test, test is usually conducted by observing the crack growth with a microscope, in this paper, new technique is tried to monitor the crack propagation in real time using optical fiber attached in the Kevlar/epoxy specimen. Crack tip position was monitored using strain distribution field data from the optical fiber and compared with the microscope data. BOCDA (Brillouin Optical Correlation Domain Analysis) system was used to measure the strain distribution of the optical fiber and spatial resolution, strain accuracy were about 9mm, +/- 20 mu epsilon each.