Liquid Resin Infusion process monitoring with superimposed Fibre Bragg Grating sensor

Abstract

International audienceThis paper reports on the instrumentation and monitoring of a fibreglass/epoxy composite manufacturing process using an optical fibre sensor based on a Bragg grating. The sensor is made of superimposed Long Period Grating (LPG) and Fibre Bragg Grating (FBG), both written on the same fibre zone. This sensor gives very accurate results and good spatial resolution, due to its ability to discriminate intrinsically between thermal and kinematic effects. The sensor was initially tested during the curing of an epoxy resin alone, in order to assess temperature and strain measurements. It is shown that these two factors can be well discriminated and quantified. The paper then presents results for monitoring Liquid Resin Infusion (LRI) , with the FBG/LPG sensor embedded in a composite part. Dielectric analysis was also performed. Results and analyses of the thermal cycle of curing and induced residual strains are discussed

Monitoring the production of FRP composites: A review of in-line sensing methods

“…The authors advise against the usage of thermocouples for flow front detection in metallic moulds, while in non-metallic they must be used with caution. Marin et al [57] wrote a long period grating (LPG) and a Bragg grating (FBG) on the same fiber zone. The superimposed gratings result in a good discrimination of thermal and kinematic strains.…”

Processing

“…Such methods include SMARTweave sensor grids [44], dielectric sensors [1,45À47], ultrasonic sensors [48,49], sensors based on fiberoptic [50À54] and Fiber Bragg Grating (FBG) systems [47,55,56], thermocouples [1,57], pressure transducers, digital camera-and photo-based systems, time-domain reflectometry (TDR) [3,58], and point-and linealvoltage sensors [59]. One basic distinction between the sensor systems can be made between sensors that collect information on the cure state or the resin position at specific locations of the mold (point-wise detection, majority of the available sensors) and sensors that cover a larger area of the mold as in, for instance, digital camera systems.…”

“…For instance, glass fiber/epoxy laminate [55,56] and carbon fiber reinforced epoxy resin composite [47,54,99] cure has been studied with FBGs; the cure of CNT reinforced epoxy resin has been monitored by an optical fiber Fresnel refractometer [100]. A fiber optic sensor integrating a refractometer and a single Bragg grating sensor has been applied to simultaneously monitor the curing reaction and the gelation onset [101].…”

Avaliação Geométrica De Canais Retangulares Em Um Processo De Infusão Por Resina

“…Como consequência, vários estudos têm sido realizados no quadro analítico, experimental e numérico, a fim de melhorar a compreensão acerca do escoamento de resina no processo de infusão (Goncharova et al, 2015). Marin (2012) descreve um método experimental para a medição de tensão e de temperatura aplicado a uma peça compósita, durante o processo de fabricação por Infusão de Resina Líquida (LRI -do inglês: Liquid Resin Infusion). O método utiliza um sensor de fibra para extrair as F. Author, S. Author, T. Author (double-click características térmicas e mecânicas do material compósito, principalmente durante o processo de cura.…”