DESIGN AND EXPERIMENTAL EVALUATION OF A COMPOSITE STRAIN ROSETTE USING FIBER BRAGG GRATING

The purpose of this study is to design a composite strain rosette using embedded fiber Bragg grating (FBG) sensors. Those strain rosettes are meant to be used as alternative to the conventional electric rosettes in structural health monitoring applications being glued at the structure surface. A thin (400 mu m) and flexible weaved carbon fiber reinforced plastic (CFRP) composite rosette is proposed. The three FBG sensors were written in a single optical fiber. Special care was devoted to the embedding process of the optical fiber sensors in the weaved composite plate in order to avoid significant alteration of the light reflected back by the FBG. The strain response of the composite rosette was compared to electrical strain gage's when applied at the surface of an aluminium sample submitted to tension, flexion and to dynamic strain. (C) 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53: 1853-1857, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26098