The distributed dynamic combined-stresses measurement of ship thruster inner-skin using fiber Bragg grating sensor rosette array

The use of a fiber Bragg grating (FBG) sensor array for the measurement of dynamic combined stress of ship thruster inner-skin is presented. The triaxial stress is detected using improved three-element rectangular rosette consisting of FBG sensors. Phase lag effect among triaxial stress sensor is considered and eliminated by employing multi-channel demodulation and improving the layout of sensor rosette array and connection layout. The tests are carried on to measure the distributed combined-stress change of ship thruster duct when ship thruster work at different rotate speed and pitch of angle. The test result are analyzed which show that measured stress are acceptable and in accord with predicted result.