Étude et évaluation des contraintes dans un tube cylindrique corrodé sous l’effet de la pression interne.

Abstract

The objective of this thesis is based on two different axes. The first is the study of the cracked pipe due to internal pressure variation and the other is the benefit of a repair to improve the life of the pipeline. First, a numerical comparative study on the behavior of an API X65 type steel pipeline was conducted, varying its thickness under variable external and internal pressure using two SolidWorks and ANSYS calculation codes. We’ve been able to get the maximum pressure the pipeline can handle. Based on these results, a circular defect of radius R = 50 mm and depth a = 2 mm was created on the outer wall and then on the inner wall and finally the two parallel defects and vice versa. The numerical results obtained show that the internal defect is the most harmful. We then looked at the creation of an external and internal rectangular crack and its effect on two tubes of an API X80M steel by varying the dimensions of the crack with a variation of the internal pressure. At the end, we carried out a numerical analysis of the effect of the semielliptical crack and a comparative study using the ANSYS software, simulating two repair methods, the first using a half-shell and the second using a composite patch (epoxy carbon). The results obtained allowed us to deduce the efficiency of the repair with an improvement in the life of the tube. In addition the composite patch repair present better results compared to the half-shell repair.