Sensors | Free Full-Text | Post-Impact Fatigue Damage Monitoring Using Fiber Bragg Grating Sensors

Sensors | Free Full-Text | Post-Impact Fatigue Damage Monitoring Using Fiber Bragg Grating Sensors

Abstract: It has been shown that impact damage to composite materials can be revealed by embedded Fiber Bragg Gratings (FBG) as a broadening and splitting of the latter’s characteristic narrow peak reflected spectrum. The current work further subjected the impact damaged composite to cyclic loading and found that the FBG spectrum gradually submerged into a rise of background intensity as internal damages progressed. By skipping the impact, directing the impact to positions away from the FBG and examining the extracted fibers, we concluded that the above change is not a result of deterioration/damage of the sensor. It is caused solely by the damages initiated in the composite by the impact and aggravated by fatigue loading. Evolution of the grating spectrum may therefore be used to monitor qualitatively the development of the incurred damages.

Keywords: fatigue; impact damage; polymer-matrix composites; health monitoring; fiber Bragg grating

An In-situ Real-Time Optical Fiber Sensor Based on Surface Plasmon Resonance for Monitoring the Growth of TiO2 Thin Films

An In-situ Real-Time Optical Fiber Sensor Based on Surface Plasmon Resonance for Monitoring the Growth of TiO2 Thin Films

Yu-Chia Tsao, Woo-Hu Tsai, Wen-Ching Shih and Mu-Shiang Wu

Sensors 2013, 13(7), 9513-9521; doi:10.3390/s130709513

Abstract: An optical fiber sensor based on surface plasmon resonance (SPR) is proposed for monitoring the thickness of deposited nano-thin films. A side-polished multimode SPR optical fiber sensor with an 850 nm-LD is used as the transducing element for real-time monitoring of the deposited TiO2 thin films. The SPR optical fiber sensor was installed in the TiO2 sputtering system in order to measure the thickness of the deposited sample during TiO2 deposition. The SPR response declined in real-time in relation to the growth of the thickness of the TiO2 thin film. Our results show the same trend of the SPR response in real-time and in spectra taken before and after deposition. The SPR transmitted intensity changes by approximately 18.76% corresponding to 50 nm of deposited TiO2 thin film. We have shown that optical fiber sensors utilizing SPR have the potential for real-time monitoring of the SPR technology of nanometer film thickness. The compact size of the SPR fiber sensor enables it to be positioned inside the deposition chamber, and it could thus measure the film thickness directly in real-time. This technology also has potential application for monitoring the deposition of other materials. Moreover, in-situ real-time SPR optical fiber sensor technology is in inexpensive, disposable technique that has anti-interference properties, and the potential to enable on-line monitoring and monitoring of organic coatings.

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BREVET : FIBER-REINFORCED NANOPARTICLE-LOADED THERMOSET POLYMER COMPOSITE WIRES AND CABLES, AND METHODS

FIBER-REINFORCED NANOPARTICLE-LOADED THERMOSET POLYMER COMPOSITE WIRES AND CABLES, AND METHODS 

Thermoset polymer composite wires including a multiplicity of substantially continuous fibers embedded in a solidified polymer composite matrix and forming a substantially continuous filament, the solidified polymer composite matrix further including a polymer formed by curing a polymer precursor from a liquid state and a multiplicity of nanoparticles having a median diameter of one micrometer or less substantially uniformly dispersed throughout the polymer composite matrix, and optionally, a corrosion resistant sheath surrounding the substantially continuous filament. In some embodiments, the multiplicity of particles includes surface-modified particles having a core and a surface modifying agent associated with the core and reacted with the polymer cured from a liquid state. Stranded cables including one or more such thermoset polymer composite wires, and methods of making and using such thermoset polymer composite wires and stranded cables are also described.

Design of nanofibres for efficient stimulated Raman scattering in the evanescent field

Design of nanofibres for efficient stimulated Raman scattering in the evanescent field
 Liye Shan , Gilles Pauliat, Guillaume Vienne, Limin Tong, Sylvie Lebrun

 Nanofibres can be produced with diameters smaller than the wavelength of the light they guide. In this regime, the guided mode presents a strong evanescent field well adapted to the excitation of "evanescent nonlinearities". We theoretically investigate such an evanescent nonlinearity: the Raman interaction between the evanescent field and a liquid surrounding the nanofibre. Our calculations demonstrate that the Raman conversion is obtained with nanofibre lengths an order of magnitude lower than those required for liquid core photonic crystal fibres.
HAL:  Design_of_nanofibres_JEOS_.pdf

Intégration de puces RFID dans les composites fibreux

Intégration de puces RFID dans les composites fibreux

Dans le monde de l'internet des objets [1], le fait d'attribuer des puces munies de codes aux objets et aux lieux permet au personnel d'une chaîne de production d'accéder rapidement à différentes informations : par exemple la nature de la pièce, qui a travaillé dessus et quelle est la prochaine étape à réaliser. Une puce d'identification transmet ces informations à un récepteur radio.

D'après Eurostat, en 2011, environ 6% des entreprises allemandes utilisaient des transpondeurs RFID dans leurs activités de production. A l'échelle de l'Europe, ce chiffre est de 4%. Maximilan Roth, ingénieur à l'Institut Fraunhofer des circuits intégrés de Nuremberg (IIS, Bavière), est convaincu que la situation va changer : "les futures applications des composites fibreux sont nombreuses, elles vont rendre la présence de puces RFID dans ces matériaux rapidement pertinente." (...)

Simulating Fiber-Reinforced Composites. It’s a multiscale world.

Simulating Fiber-Reinforced Composites. It’s a multiscale world

Composite materials, and particularly fiber-reinforced composites, present an interesting challenge. They have superior properties, compared to homogeneous materials, and have the potential to help engineers and designers meet increasingly challenging product requirements. Yet, they can be maddeningly difficult to engineer properly.

To understand why this is so, you need to look closely, at the structure of composites(...)

Fatigue equation considerations for the American Society of Civil Engineers pre-standard for load and resistance factor design of pultruded fiber-reinforced polymer structures

Fatigue equation considerations for the American Society of Civil Engineers pre-standard for load and resistance factor design of pultruded fiber-reinforced polymer structures

A recently completed pre-standard for load and resistance factor design of pultruded fiber-reinforced polymer structures includes an S-N fatigue life prediction model for the design of components, which will experience cyclic loading. The prediction is independent of material and geometric properties and is shown to be overly conservative when applied to experimental data. A different model, developed at the Constructed Facilities Center at West Virginia University, is combined with the pre-standard model in order to incorporate material and geometric properties and improve life prediction accuracy from an over-prediction of 50x cycles to failure to only 5x.

Creating smart fiber composites by embedding ultrathin RFID tags

Creating smart fiber composites by embedding ultrathin RFID tags

(Nanowerk News) Antennas that are capable of transmitting radio waves turn components into intelligent objects. Researchers have now found a way to embed these antennas in fiber composites. As a result, the technology also works with carbon and glass fibers.

Read more: http://www.nanowerk.com/news2/newsid=31105.php#ixzz2YAsjbGiU

Pultrusion and Fiberline Structural Profiles

Pultrusion and Fiberline Structural Profiles

FiberlineComposites

Fiberline manufactures GRP structural profiles which provide a sophisticated alternative to concrete, steel, aluminium and wood. Pultrusion is a process that enables continuous production of ....