Strain measurements : a comparison of strain gauge and fiber bragg grating measurements on KNM Skjold

Strain measurements by means of resistive strain gauges and fiber optic Bragg gratings during the sea-keeping tests of KNM Skjold have been analyzed and compared. The resistive strain gauge measurements were severely affected by noise. The signals have been filtered. synchronized and compared using extreme values as well as vector analysis. Results indicate that the two techniques measure the same strain levels. however fiber optic sensor measurements are superior concerning low noise and reliability