Real-time cure monitoring of smart composite materials using extrinsic Fabry-Perot interferometer and fiber Bragg grating sensors

2002 ◽  
Vol 11 (2) ◽  
pp. 249-255 ◽  
Author(s):  
J S Leng ◽  
A Asundi
Keyword(s):  
Composite Materials ◽  
Fiber Bragg Grating ◽  
Real Time ◽  
Bragg Grating ◽  
Smart Composite ◽  
Cure Monitoring ◽  
Fiber Bragg Grating Sensors ◽  
Fabry Perot ◽  
Smart Composite Materials

Cognitive fiber Bragg grating sensors system based on fiber Fabry-Perot tunable filter technology

2011 ◽  
Author(s):  
Hongtao Zhang ◽  
Pengfei Wang ◽  
Jilin Zou ◽  
Jing Xie ◽  
Hong-Liang Cui
Keyword(s):  
Fiber Bragg Grating ◽  
Tunable Filter ◽  
Bragg Grating ◽  
Fiber Bragg Grating Sensors ◽  
Fabry Perot

scholarly journals Real-Time Train Wheel Condition Monitoring by Fiber Bragg Grating Sensors

2011 ◽  
Vol 8 (1) ◽  
pp. 409048 ◽  
Author(s):  
Chuliang Wei ◽  
Qin Xin ◽  
W. H. Chung ◽  
Shun-yee Liu ◽  
Hwa-yaw Tam ◽  
...  
Keyword(s):  
Fiber Bragg Grating ◽  
Real Time ◽  
Visual Inspection ◽  
Condition Index ◽  
Bragg Grating ◽  
Time System ◽  
Real Time System ◽  
Fiber Bragg Grating Sensors ◽  
Extensive Field ◽  
The Cost

Wheel defects on trains, such as flat wheels and out-of-roundness, inevitably jeopardize the safety of railway operations. Regular visual inspection and checking by experienced workers are the commonly adopted practice to identify wheel defects. However, the defects may not be spotted in time. Therefore, an automatic, remote-sensing, reliable, and accurate monitoring system for wheel condition is always desirable. The paper describes a real-time system to monitor wheel defects based on fiber Bragg grating sensors. Track strain response upon wheel-rail interaction is measured and processed to generate a condition index which directly reflects the wheel condition. This approach is verified by extensive field test, and the preliminary results show that this electromagnetic-immune system provides an effective alternative for wheel defects detection. The system significantly increases the efficiency of maintenance management and reduces the cost for defects detection, and more importantly, avoids derailment timely.

Measurement of the Thermal Expansion for Space Structures Using Fiber Bragg Grating Sensors and Displacement Measuring Interferometers

2008 ◽  
Author(s):  
Hong-Il Kim ◽  
Lae-Hyong Kang ◽  
Jae-Hung Han
Keyword(s):  
Fiber Bragg Grating ◽  
Real Time ◽  
Deformation Monitoring ◽  
Space Environment ◽  
Space Structures ◽  
Bragg Grating ◽  
Environment Change ◽  
Time Deformation ◽  
Fiber Bragg Grating Sensors ◽  
Fbg Sensors

Dimensional stability of the space structures, such as large telescope mirrors or metering substructures, is very important because even extremely small deformations of these structures might degrade the optical performances. Therefore, precise deformation data of the space structures according to environment change are required to design these structures correctly. Also, real-time deformation monitoring of these structures in space environment is demanded to verify whether these structures are properly designed or manufactured. FBG (fiber Bragg grating) sensors are applicable to real time monitoring of the space structure because they can be embedded onto the structures with minimal weight penalty. In this research, therefore, thermal deformation measurement system for the space structures, composed of FBG sensors for real time strain measurement and DMI (displacement measuring interferometers) for accurate specimen expansion data acquisition, is developed. Thermal strains measured by distributed FBG sensors are evaluated by the comparison with the strains obtained by highly accurate DMI.

scholarly journals Applicability of fiber Bragg grating sensors for cure monitoring in resin transfer molding processes

2020 ◽  
pp. 073168442095811
Author(s):  
Yannick Blößl ◽  
Gergely Hegedüs ◽  
Gábor Szebényi ◽  
Tamás Tábi ◽  
Ralf Schledjewski ◽  
...  
Keyword(s):  
Fiber Bragg Grating ◽  
Resin Transfer Molding ◽  
Sol Gel ◽  
Bragg Grating ◽  
Gel Point ◽  
Strain Response ◽  
Resin System ◽  
Transfer Molding ◽  
Cure Monitoring ◽  
Fiber Bragg Grating Sensors

This article examines the use of fiber Bragg grating sensors for cure monitoring purposes in resin transfer molding processes. Within a resin transfer molding test series a thermoset epoxy-amine resin system was used in combination with a woven flax fiber reinforcement. Particular attention was paid on the location of the optical fiber sensor and its sensitive Bragg grating element inside the mold cavity. Three different installation approaches were tested and the correlation of the corresponding strain response with the actual cure state of the resin system was investigated at 50°C and 70°C isothermal cure temperature, respectively. We could demonstrate that characteristic, conspicuous strain changes are directly related to the sol–gel conversion of the thermoset polymer, which was analyzed considering different approaches for the gel-point detection based on rheological measurements. With the installation of the sensor inside a controllable, capsuled resin volume, we could achieve the most reliable strain response that provides capabilities to give in-situ information of the cure state beyond the gelation point.

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