Name: GABRIEL FRACALOSSI FEIJÓ
Publication date: 27/02/2024
Examining board:
Name |
Role |
|---|---|
| JUAN MANUEL PARDAL | Coorientador |
| MARCELO CAMARGO SEVERO DE MACEDO | Presidente |
| OLGA LISKEVYCH | Examinador Externo |
| SÉRGIO SOUTO MAIOR TAVARES | Examinador Externo |
Summary: Flexible pipelines are used in the oil industry to transport oil and gas, being considered an advantageous option for the challenges encountered in the exploration of deeper areas, such as the pre-salt. These ducts are made up of different layers, including the traction reinforcement, made up of steel wires, which are responsible for resisting traction, compression and radial loads applied to this component. Due to the application of complex stress modules, their failure modes can become unpredictable, therefore, verify their integrity becomes essential. The use of electromagnetic techniques presents itself as a good method for the non-destructive evaluation of these materials. The present work aims to present information that makes it possible to understand the influence of residuals stress on the behavior of Barkhausen magnetic noise. To do this, the residuals stress in the flexible tubes will be tested and correlated with the rotational parameters of the Barkhausen magnetic noise and the envelope behavior of this same method. To this end, in the experimental stage, the residual stress will be proven, using the hole drilling method, in the direction of bending transverse, bending and 45º bending transversal. Next, the Barkhausen magnetic noise rotation test will be carried out at frequencies of 50 Hz and 125 Hz. After the experimental part, the RMS parameters and the Barkhausen magnetic noise envelope will be analyzed and correlated with the variation in residual stress. It is worth mentioning that with plastic deformation there is the development of crystalline anisotropy, which also directly influences the results collected. Note that the rotational RMS presents a more objective characterization of crystalline anisotropy, while the Barkhausen magnetic noise envelope presents a better understanding of the residual stress variation in the tested samples but is a challenge to separating the influence of residuals stress in the envelope of magnetic noise in materials that present crystalline anisotropy.
