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Pipelines are subject to a variety of defects such as wall thickness loss, grooves, dents and holes. To restore the pipe integrity, polymeric composite repairs can be used. The inspection of repaired pipes is of fundamental importance, not only to verify the initial integrity, but also to monitor their state over time. Shearography is a laser optical strain measurement technique which compares a strain image in unstressed and stressed conditions to reveal the presence of defects and provides useful information about the interface between the repair and substrate, identifying delamination, interfacial disbond and holes. In this work, two pipes repaired with composites from two different providers were submitted to shearography inspection in order to analyze the repair system integrity. The inspections were performed to verify the presence or absence of detachments between the composite repair and subtracts and/or between the layers of the repair itself. After the procedure, the repairs were removed to compare and confirm the inspection results. Repair A presented some difficulty to be removed, what is in accordance with shearography results that exhibited the presence of only some superficial defects. The pipe surface aspect after composite removal was good, without any type of corrosion. On the other hand, the shearography inspection of repair B indicated lack of adhesion between the steel pipe and the composite repair. The repair removal was very easy, corroborating the inspection results. Also, it was observed that the pipe surface presented metal oxides. Through these inspections it could be noted an excellent correlation between shearography inspection results and the degree of difficulty to remove the repairs. The results from an inspection in an offshore platform are also presented. This inspection showed that shearography is an efficient method to inspect steel pipes repaired with composite materials in field.

O interesse no monitoramento de equipamentos em tempo real é crescente nos dias de hoje, visando a maior segurança de operação dos mesmos. O ensaio de Emissão Acústica vem sendo objeto de desenvolvimentos com o intuito de aplicação em diversos tipos de equipamentos, com destaque na inspeção de dutos rígidos e flexíveis. O presente trabalho apresenta a metodologia e os resultados obtidos de um estudo de aplicação do método de Emissão Acústica para detectar defeitos em propagação em dutos rígidos pressurizados, sendo um trabalho pioneiro nessa área de pesquisa. Para tal, foram confeccionados corpos de prova com defeitos inseridos artificialmente, empregando-se a técnica de ultrassom por Time-of-flight diffraction (TOFD) para acompanhar o crescimento dos defeitos no duto submetido a ensaio hidrostático. Os sinais resultantes foram divididos em classes de Propagação, Propagação Estável e Propagação Instável, e usados como dados de entrada na implementação de classificadores não lineares via Redes Supervisionadas do tipo Retropropagação do Erro. Os resultados atingiram acertos de classificação próximos a 86%, comprovando a eficiência do método para as condições testadas até o presente momento.