COMPOSITE MATERIAL DAMAGE MONITORING USING EMBEDDED IN POLYMER MATRIX OPTICAL FIBER BRAGG GRATING OR LONG PERIOD GRATING SENSORS

A new method of detecting how a crack appears and grows, as a damage, in fiber reinforced polymer composite material using embedded Fiber Bragg Grating (FBG) and/or Long Period Grating Fiber Sensors (LPGFS) is presented. Different features of the crack mechanism that induce a change in the FBG sensor or LPGFS response are identified. The response of FBG sensor or LPGFS under host composite material host crack action is investigated and simulated for defining the functional limits of the composite material. FBG sensor or LPGFS are considered as embedded in polymer matrix of composite material.