Low Speed Impact of Woven Fiber Composites Including Fiber Bragg Grating Sensors

2009 ◽  
Author(s):  
K. C. Liu ◽  
Cris Hiche ◽  
Aditi Chattopadhyay
Keyword(s):  
Fiber Bragg Grating ◽  
Impact Damage ◽  
Composite Plates ◽  
Optimal Location ◽  
Bragg Grating ◽  
Strain Response ◽  
Fiber Bragg Grating Sensors ◽  
Flash Thermography ◽  
Impact Energies ◽  
The Impact

In this paper, the dynamic Fiber Bragg Grating sensor response due to low speed impact on woven fiber composite plates was used to determine the extent of the impact damage. Three types of woven fabrics were considered in this study: plain, twill and 5 harness satin. A brief finite element analysis was used to determine the optimal location for the sensors. The bottom of the plate showed the highest strain response and was chose as the optimal location. The composite plates were fabricated and Fiber Bragg Grating sensors were mounted in the optimal location. The plates were subject to various impact energies using a modified Charpy impactor. The impact damage for each plate due to different impact energies was quantified through flash thermography and correlated with the FBG response. The flash thermography results showed excellent progression of damage in the plates and the sensor strain response was able to distinguish the impacts by considering both peak and plastic strain.

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.

Impact source identification for pipe structure based on a one-dimensional fiber Bragg grating sensor array

2017 ◽  
Vol 28 (12) ◽  
pp. 1662-1669 ◽  
Author(s):  
Yeon-Gwan Lee ◽  
Chun-Gon Kim
Keyword(s):  
Fiber Bragg Grating ◽  
Source Identification ◽  
Sensor Array ◽  
Bragg Grating ◽  
One Dimensional ◽  
Fiber Bragg Grating Sensors ◽  
Sensor Arrangement ◽  
Impact Location ◽  
Bragg Grating Sensor ◽  
The Impact

This article presents a spatial impact source identification based on a one-dimensional fiber Bragg grating sensor array for application in tubular structures. The effective number of sensors and the sensor arrangement method were investigated for the plumbing pipe structure as the application subject. The fiber Bragg grating sensors were used to determine the impact location via the signal processing of the measured acoustic emission signals with a sampling frequency of 100 kHz. The root mean squared value–based algorithm, which was newly verified for a stiffened composite structure, was employed to identify the impact source in this article. Impact source identification was implemented according to the sensor arrangement and number of sensors, which were selectively used on the pipe structure among six multiplexed fiber Bragg grating sensors in one optical fiber line. This process shows that impact location detection is possible with only a one-dimensional sensor array compared to the results of a two-dimensional sensor array. The impact location could be predicted within a maximum error range of 31.12 mm, even if only one sensor was used to identify the impact source.

scholarly journals Fiber Bragg Grating Sensors for Underwater Vibration Measurement: Potential Hydropower Applications

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4272
Author(s):  
Oscar de la Torre ◽  
Ignazio Floris ◽  
Salvador Sales ◽  
Xavier Escaler
Keyword(s):  
Fiber Bragg Grating ◽  
Numerical Models ◽  
Vibration Measurement ◽  
Quality Data ◽  
Bragg Grating ◽  
Laser Vibrometer ◽  
Main Concern ◽  
High Expectations ◽  
Fiber Bragg Grating Sensors ◽  
Hydraulic Machinery

The present paper assesses the performance and characteristics of fiber Bragg grating sensors, with a special interest in their applications in hydraulic machinery and systems. The hydropower industry is turning to this technology with high expectations of obtaining high quality data to validate and calibrate numerical models that could be used as digital twins of key assets, further strengthening the sector’s relevant position within industry 4.0. Prior to any validation, fiber Bragg grating sensors’ ability to perform well underwater for long periods of time with minimal degradation, and their ease of scalability, drew the authors´ attention. A simplified modal analysis of a partially submerged beam is proposed here as a first step to validate the potential of this type of technology for hydropower applications. Fiber Bragg grating sensors are used to obtain the beam’s natural frequencies and to damp vibrations under different conditions. The results are compared with more established waterproof electric strain gauges and a laser vibrometer with good agreement. The presence of several sensors in a single fiber ensures high spatial resolution, fundamental to precisely determine vibration patterns, which is a main concern in this industry. In this work, the beam’s vibration patterns have been successfully captured under different excitations and conditions.

Estimating needle-tissue interaction forces for hollow needles using fiber Bragg grating sensors

2016 ◽  
Author(s):  
Saurabh Kumar ◽  
V. Shrikanth ◽  
Bharadwaj Amrutur ◽  
Sundarrajan Asokan ◽  
M. S. Bobji
Keyword(s):  
Fiber Bragg Grating ◽  
Bragg Grating ◽  
Interaction Forces ◽  
Tissue Interaction ◽  
Fiber Bragg Grating Sensors
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