New design for temperature-strain discrimination using fiber Bragg gratings embedded in laminated composites

Abstract

A new smart structure based on fiber Bragg gratings (FBGs) embedded into composite laminates for temperature and strain simultaneous measurement has been designed and experimentally tested. Two holes have been drilled at preset locations in the composite plate to create different strain sensitivities at different locations. The proposed design has been compared to three reference sensing heads also based on embedding FBGs into composite materials. Experimental results agree remarkably well with mechanical simulations and validate all the tested designs for the temperature–strain discrimination. Based on the same principle, another sensing head with a long single FBG embedded has also been designed and experimentally tested, obtaining temperature independent strain measurement.