TY - JOUR

T1 - Gel Point Determination in Resin Transfer Molding Process with Fiber Bragg Grating Inscribed in Side-Hole Elliptical Core Optical Fiber

AU - Wachtarczyk, Karol

AU - Bender, Marcel

AU - Fauster, Ewald

AU - Schledjewski, Ralf

AU - Gąsior, Paweł

AU - Kaleta, Jerzy

PY - 2022/9/19

Y1 - 2022/9/19

N2 - Material as well as process variations in the composites industry are reasons to develop methods for in-line monitoring, which would increase reproducibility of the manufacturing process and the final composite products. Fiber Bragg Gratings (FBGs) have shown to be useful for monitoring liquid-composite molding processes, e.g., in terms of online gel point detection. Existing works however, focus on in-plane strain measurements while out-of-plane residual strain prevails. In order to measure out-of-plane strain, FBG inscribed in highly birefringent fiber (HB FBG) can be used. The purpose of this research is the cure stage detection with (a) FBG inscribed in single mode and (b) FBG inscribed in highly-birefringent side-hole fiber in comparison to the reference gel point detected with an in-mold DC sensor. Results reveal that the curing process is better traceable with HB FBG than with regular FBG. Thus, the use of HB FBG can be a good method for the gel point estimation in the RTM process.

AB - Material as well as process variations in the composites industry are reasons to develop methods for in-line monitoring, which would increase reproducibility of the manufacturing process and the final composite products. Fiber Bragg Gratings (FBGs) have shown to be useful for monitoring liquid-composite molding processes, e.g., in terms of online gel point detection. Existing works however, focus on in-plane strain measurements while out-of-plane residual strain prevails. In order to measure out-of-plane strain, FBG inscribed in highly birefringent fiber (HB FBG) can be used. The purpose of this research is the cure stage detection with (a) FBG inscribed in single mode and (b) FBG inscribed in highly-birefringent side-hole fiber in comparison to the reference gel point detected with an in-mold DC sensor. Results reveal that the curing process is better traceable with HB FBG than with regular FBG. Thus, the use of HB FBG can be a good method for the gel point estimation in the RTM process.

KW - fiber optic sensors

KW - Fiber Bragg Grating

KW - high birefringent fibers

KW - side-hole optical fiber

KW - Resin transfer molding (RTM)

KW - Cure monitoring

KW - gel point estimation

KW - residual stress

UR - https://www.mdpi.com/journal/materials/special_issues/Manufacturing_Composite

U2 - 10.3390/ma15186497

DO - 10.3390/ma15186497

M3 - Article

VL - 15.2022

JO - Materials

JF - Materials

SN - 1996-1944

IS - 18

M1 - 6497

ER -