| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 10.36 MB | Adobe PDF |
Authors
Abstract(s)
Nesta dissertação é apresentado um trabalho de investigação inovador sobre a
monitorização, em tempo real, de materiais compósitos com sensores ópticos embebidos
sujeitos a ciclos de carga e descarga em regime elástico.
Os materiais compósitos possuem propriedades vantajosas sobre os metais e os
materiais cerâmicos, nomeadamente a sua relação tensão/peso e a possibilidade de
embebimento de sensores.
Neste trabalho foram utilizadas fibras ópticas na monitorização, em tempo real, de
laminados de fibra de carbono com dois diferentes empilhamentos.
Foram fabricados laminados de fibra de carbono com três diferentes números de
camadas (18,22,26), diferentes configurações de empilhamento, com e sem fibra ópticas
(sensor) incorporadas, de modo a estudar as diferenças nas propriedades dos materiais
compósitos com a incorporação da fibra óptica e na resposta do sinal óptico em função do
posicionamento da fibra, do número de camadas e da sequência de empilhamento.
Os laminados foram testados à flexão com três pontos com um sinal luminoso
constante nas fibras ópticas alimentado por um laser e recebido por um sensor de
luminosidade. Os resultados foram obtidos através de um sistema de aquisição de dados que
permitiu a obtenção sincronizada dos resultados da variação da potência do sinal óptico, dos
dados da deformação e força aplicada.
Desta forma obteve-se a resposta com maior sensibilidade na detecção de
deformações, na região elástica, para uma efectiva monitorização da estrutura, em tempo
real, e possível aplicação na futura manutenção de sistemas.
This dissertation contains an innovative research work concerning the monitoring of composites, in real-time, subjected to cycles of loading and unloading in the elastic region, with embedded optical sensors. Composite materials have advantageous properties over metal and ceramic materials, such as their tension/weight relation and the possibility of embedment of sensors. In this work, optical fiber was utilized for monitoring in real-time the carbon fiber laminates with two different stacks. The laminates of carbon fiber were manufactured with three different number of layers (18,22,26), different configurations of stacking, with and without optical fibers (sensor) incorporated, in order to study the differences in the properties of composite materials with incorporated optical fibers and the signal response according to the positioning of the optical fiber, number of layers and the stacking sequence. The laminates were tested by bending with three points with a constant light signal in the optical fibers, fed by a laser and received by a light sensor. The results were obtained through a data acquirement system that allowed the synchronized attainment of results of the variation of the optical signal potency, data of the deformation and applied force. Thus it was obtained the response with greater sensitivity for the deformation detection, in the elastic region, for an effective monitoring of the structure, in real time, and possible applications in future systems maintenance.
This dissertation contains an innovative research work concerning the monitoring of composites, in real-time, subjected to cycles of loading and unloading in the elastic region, with embedded optical sensors. Composite materials have advantageous properties over metal and ceramic materials, such as their tension/weight relation and the possibility of embedment of sensors. In this work, optical fiber was utilized for monitoring in real-time the carbon fiber laminates with two different stacks. The laminates of carbon fiber were manufactured with three different number of layers (18,22,26), different configurations of stacking, with and without optical fibers (sensor) incorporated, in order to study the differences in the properties of composite materials with incorporated optical fibers and the signal response according to the positioning of the optical fiber, number of layers and the stacking sequence. The laminates were tested by bending with three points with a constant light signal in the optical fibers, fed by a laser and received by a light sensor. The results were obtained through a data acquirement system that allowed the synchronized attainment of results of the variation of the optical signal potency, data of the deformation and applied force. Thus it was obtained the response with greater sensitivity for the deformation detection, in the elastic region, for an effective monitoring of the structure, in real time, and possible applications in future systems maintenance.
Description
Keywords
Materiais compósitos Materiais sensoriais Fibras ópticas Laminados compósitos
Citation
Publisher
Universidade da Beira Interior