COMPOSITE STRUCTURE RESIN CURE MONITORING USING AN OPTICAL FIBER GRATING SENSOR

摘要

Resin curing of a composite laminated structure is monitored using an optical fiber 20 having a grating sensor 28 embedded therein. The fiber 20 is surrounded by upper and lower buffer regions 12,14 having a predetermined minimum number of layers 30 (or thickness) with uni-directional reinforcing filaments 32 and resin 34 therebetween. When the filaments 32 are oriented perpendicular to the longitudinal axis of the fiber 20, the buffer regions 12,14 allow the sensor 28 to exhibit maximum sensitivity to detection of the minimum resin viscosity and the gelation point (i.e., the onset of a rapid crosslinking rate) of the resin 34. The buffer regions 12,14 also have a minimum thickness which serve to isolate the sensor 28 from interfering stresses from arbitrarily angled filaments 32 in layers 30 of outer regions 10,16 which surround the buffer regions 12,14.