Résumé:
The aim of this project is to experimentally study the effect of semi-elliptical defects on API
X52 pipeline steel and its repair by welding and by patching with hybrid composites made of
natural fibers and synthetic materials. Tensile tests were performed on API X52 steel samples,
with and without semi-elliptical defects through the variation of a/c and a/t ratios, and then the
samples repaired by welding and composite patches were tested and compared with the results
of origin material samples. The experimental results of mechanical properties indicate the
effect of defects on the integrity of the pipeline of energy transport through the different ratios
of a/c and a/t. It was observed that a/t ratio defects are more dangerous than the ratio a/c,
especially when the ratio a/t is higher than 0.5. It is clear that both welding repair and
composite patch methods can be considered as a solution for maintaining the integrity of the
piping systems.