Embedded FBG Sensor in Aircraft Smart Composite Materials for Structural Monitoring

Abstract

This paper describes the use of embedded Fiber Brag Grating (FBG) sensor in the honeycomb core carbon fiber sandwich panel in smart composite materials for the application of monitoring the structural integrity of an aircraft. A part of vertical stabilizer was selected and reproduced using carbon fiber honeycomb core sandwich panels. The sandwich panel was fabricated in accordance to the generic sandwich structure and aviation industry standards, including the materials and also the method of construction. Using a carbon fiber from Hexcel as the face-sheet, Nomex honeycomb as the core, the sandwich panel was cured using Hysol EA9330 resin according to a standard curing process in the aviation industry. In order to make the sandwich panel as smart materials, optical sensor which has fiber bragg grating arrays, FBG, were embedded between the carbon fiber plies during the lay-out process. Using an FBG data logger and Instron 8802 Universal Testing Machine, the panel was subjected to flexural load and the FBG sensor signals were read at the load interval of 0.2 kN. From the experiment the results were taken and data was plotted and it shows that the FBG signals responded well to the load applied. In the future, the specimen will be used for further experiment for measuring strains and establishing the existence of damage in the panel.