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Ensaios por ultrassons em compĆ³sitos laminados de parede fina com tecnologia de Phased Array
| Name: | Description: | Size: | Format: | |
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| 9.13 MB | Adobe PDF |
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Abstract(s)
A sustentabilidade Ć©, cada vez mais uma prioridade da indĆŗstria e da sociedade. Isto leva Ć utilizaĆ§Ć£o mais extensiva de materiais compĆ³sitos laminados de PolĆmero ReforƧado por Fibra. Isto permite reduzir o peso de estruturas, melhorando propriedades mecĆ¢nicas acrescendo a maior eficiĆŖncia energĆ©tica de transportes. Por outro lado, o seu controlo, apresenta novos desafios para a indĆŗstria. Para dar resposta a este estĆmulo industrial, Ć© necessĆ”rio criar know-how no ensino, relativo a estes materiais e aos processos que o tratam. Este trabalho atua na vertente de comeƧar a aprofundar este conhecimento. Para se conseguir garantir a qualidade de algo Ć© preciso saber-se o que pode correr mal tendo-se listado e especificado os diferentes ādefeitosā tĆpicos deste tipo de materiais. Seguidamente, elaborou-se uma exposiĆ§Ć£o relativa ao funcionamento dos ensaios por ultrassons, quer convencionais, quer por āPhased Arrayā. Nesta foram exibidos alguns exemplos teĆ³ricos, mostrados equipamentos, e comparados mĆ©todos. Para possibilitar o inĆcio da experimentaĆ§Ć£o e testagem, foi estudado um conjunto de parĆ¢metros que pudesse ser utilizado como ponto de partida para futuros trabalhos acadĆ©micos. Estes foram especificados para defeitos de delaminaĆ§Ć£o e danos de pequenas dimensƵes. Este estudo foi realizado com recurso a phased array em provetes de fibra de carbono. Por fim, concluiu-se que, com uma abertura entre os 6 e os 8 elementos e com frequĆŖncias de 10MHz de processamento do sinal, seria possĆvel detetar todos os patramares-teste de delaminaĆ§Ć£o e a maioria dos defeitos de pequena dimensĆ£o.
Sustainability is, increasingly, becoming a priority, both for industry and society. This results in the rampant use of laminate composite materials such as Fiber Reinforced Composites. This allows a drastic weight reduction in structures, while improving both mechanical properties, and energy efficiency in transportation. However, Quality control is presented with new challenges. To answer this industrial stimulus, the creation of academic knowhow, regarding these materials and processes, is critical. This essay aims to fill the knowledge gap between academia and Industry. To ensure the quality of something, there needs to be a notion of what might go wrong with it, requiring the listing and specification of those possible non-conformities typical of those materials. Then, an exposition was made, regarding the elemental functioning of Ultrasound testing, both conventional and using Phased Array technology. Here were exposed machines, capabilities, examples and comparisons using both methods. To allow the beginning of further experimentation, a study allowed the creation of a window of parameters, which would serve as a launch point for further academic studies. These parameters were studied for delamination and low velocity impact damage defects in carbon fiber specimens, using phased array ultrasound methods. In the end, using apertures between 6 and 8 elements, and frequencies ranging around 10MHz, it was possible to detect all the delamination test defects, as well as the low volume test defects.
Sustainability is, increasingly, becoming a priority, both for industry and society. This results in the rampant use of laminate composite materials such as Fiber Reinforced Composites. This allows a drastic weight reduction in structures, while improving both mechanical properties, and energy efficiency in transportation. However, Quality control is presented with new challenges. To answer this industrial stimulus, the creation of academic knowhow, regarding these materials and processes, is critical. This essay aims to fill the knowledge gap between academia and Industry. To ensure the quality of something, there needs to be a notion of what might go wrong with it, requiring the listing and specification of those possible non-conformities typical of those materials. Then, an exposition was made, regarding the elemental functioning of Ultrasound testing, both conventional and using Phased Array technology. Here were exposed machines, capabilities, examples and comparisons using both methods. To allow the beginning of further experimentation, a study allowed the creation of a window of parameters, which would serve as a launch point for further academic studies. These parameters were studied for delamination and low velocity impact damage defects in carbon fiber specimens, using phased array ultrasound methods. In the end, using apertures between 6 and 8 elements, and frequencies ranging around 10MHz, it was possible to detect all the delamination test defects, as well as the low volume test defects.
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Keywords
Ensaios por Ultrassons PolĆmeros ReforƧados por Fibra DelaminaĆ§Ć£o Fiber Reinforced Composites Ultrasound Testing Phased Array Delamination