The Impact of Embedding Four Different Kinds of FBGs on the Strength of the Carbon Fiber Structure

This study embeds four types of fiber Bragg gratings (FBGs)-SM-FBG, M-FBG, PI-FBG, and Normal-FBG-into composite structures and assesses their embedding feasibility through tensile and compression tests on carbon fiber specimens. Results show that M-FBG has the highest survival rate, followed by SM-FBG, while Normal-FBG has the lowest due to coating carbonization during curing. Embedding FBGs affects the tensile Young's modulus by less than 10%, and the compressive modulus by up to 17.7%. With SM-FBG achieving the highest compressive strength and the minimal impact on carbon fiber modulus. The relative difference in compressive modulus for SM-FBG is 8.2 %, with a relative difference in tensile modulus of 7.5<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">%</sup> at 0 degrees and 0.8% at 90 degrees. Therefore, the FBGs used in this experiment are all capable of strain sensing, with SM-FBG being more suitable as a strain sensor for carbon fiber structural components.