Application Issues Using Fibre Bragg Gratings as Strain Sensors in Fibre Composites

: Fibre Bragg grating sensors have been developed as a strain measurement technique. With regard to practical applications, there is growing knowledge and experience. However, many application issues remain unsolved. These issues include signal interpretation, confidence in measurement accuracy, calibration, and zero-strain definition. This paper reports some issues which have been encountered in practical measurements and application trials. The investigation covers various aspects of strain measurement. The measurement accuracy in a composite laminate is found to be influenced by the formation of cracks in adjoined layers, interface between fibre sensor and host materials and nonuniform stress fields.