Cure monitoring of cross-ply composite laminates with an encapsulated fibre Bragg grating

2012 ◽  
pp. 175-179 ◽  
Author(s):  
G Luyckx ◽  
N Lammens ◽  
J Degrieck ◽  
E Voet
Keyword(s):  
Composite Laminates ◽  
Bragg Grating ◽  
Fibre Bragg Grating ◽  
Cure Monitoring

High Strain Monitoring during Fatigue Loading of Thermoplastic Composites Using Imbedded Draw Tower Fibre Bragg Grating Sensors

2008 ◽  
Vol 56 ◽  
pp. 441-446 ◽  
Author(s):  
Eli Voet ◽  
Geert Luyckx ◽  
Ives De Baere ◽  
Joris Degrieck ◽  
J. Vlekken ◽  
...  
Keyword(s):  
Composite Laminates ◽  
High Strength ◽  
Fatigue Loading ◽  
Strain Sensors ◽  
Thermoplastic Composites ◽  
Bragg Grating ◽  
Fibre Bragg Grating ◽  
Strain Measurements ◽  
Strain Monitoring

This paper presents the experimental study of fibre Bragg grating sensors for measuring strain inside composite laminates during fatigue loading. The optical fibres are imbedded inside thermoplastic CFRP test-coupons which have an ultimate strain of about 1.1%. Tension – tension fatigue cycling at a rate of 5Hz is been carried out at 314MPa with a maximum strain of 0.51%. At such extreme strain levels the use of high strength sensors becomes inevitable. Neither the sensor nor the composite test-coupons showed any significant degradation even after more than 500000 cycles. Fibre optic Bragg grating sensors are known to be very accurate strain sensors but one should be very careful interpreting their response once they are imbedded inside composite materials. In this study high strength fibre Bragg grating sensors with coating are imbedded in composite test coupons and a pretty good correlation was found between the strain measurements of an electrical extensometer and the imbedded sensor during the complete cycling. The high strength sensor show to be very feasible for extreme and long term strain measurements.

In-situ impact-induced damage assessment of woven composite laminates through a fibre Bragg grating sensor network

2009 ◽  
Vol 113 (1144) ◽  
pp. 357-370 ◽  
Author(s):  
R. C. Garrett ◽  
K. J. Peters ◽  
M. A. Zikry
Keyword(s):  
Sensor Network ◽  
Composite Laminates ◽  
Contact Forces ◽  
Bragg Grating ◽  
Residual Lifetime ◽  
Fibre Bragg Grating ◽  
Woven Composite ◽  
Average Residual ◽  
Residual Strains ◽  
Critical Damage

Abstract Woven composite specimens with embedded fibre Bragg grating (FBG) sensor networks were impacted at low velocities, while global measurements of contact forces and dissipated energies were obtained from drop tower measurements, and local residual, post-impact strain values were obtained from the FBG sensors. Critical damage events were identified in the global data for these specimens and damage signatures in the residual strain data corresponding to these critical damage events were correlated. The results indicate that the full spectral scan information from the sensor network, although obtainable at a lower scan rate, provide more reliable residual lifetime information than average residual strains.

Characteristics of Fiber Bragg Grating Sensors with Various Grating Lengths Embedded in Composite Materials

2006 ◽  
Vol 321-323 ◽  
pp. 152-155 ◽  
Author(s):  
Dong Hoon Kang ◽  
Chang Sun Hong ◽  
Chun Gon Kim
Keyword(s):  
Composite Materials ◽  
Fiber Bragg Grating ◽  
Composite Laminates ◽  
Fiber Optic Sensors ◽  
Bragg Grating ◽  
Cure Monitoring ◽  
Signal Characteristics ◽  
Reinforcing Fibers ◽  
Fbg Sensors ◽  
Application Fields

Because of their good multiplexing capabilities, fiber Bragg grating (FBG) sensors are being studied more actively than any of other fiber optic sensors. The application fields of FBG sensors have been mainly focused on composite materials through embedding rather than through surface attachments. However, there are many limitations on the embedding of FBG sensors into composite materials because of the birefringence that is induced when FBG sensors are not embedded parallel to the reinforcing fibers. This study investigates the fabrication of FBG sensors that have various grating lengths, good multiplexing capabilities, better stability from birefringence, and ease in production. The signal characteristics of FBG sensors are also verified through the cure monitoring of two composite laminates.

Amplification of fibre Bragg grating reflectivity by post-writing exposure with a 193 nm ArF laser

1994 ◽  
Vol 30 (14) ◽  
pp. 1133-1134 ◽  
Author(s):  
P. E. Dyer ◽  
K. C. Byron ◽  
R. J. Farley ◽  
R. Giedl
Keyword(s):  
Bragg Grating ◽  
Fibre Bragg Grating ◽  
Arf Laser ◽  
193 Nm

Microwave phase shifter based on fibre Bragg grating

1998 ◽  
Vol 34 (21) ◽  
pp. 2051 ◽  
Author(s):  
B. Ortega ◽  
J.L. Cruz ◽  
M.V. Andrés ◽  
A. Díez ◽  
D. Pastor ◽  
...  
Keyword(s):  
Phase Shifter ◽  
Bragg Grating ◽  
Fibre Bragg Grating ◽  
Microwave Phase Shifter
Sign in / Sign up

Export Citation Format

Share Document