Avaliação de concentração de tensão em dutos danificados sob pressão interna após reparo

Abstract

This study evaluates the stress concentration of plain dents due to mechanical damage in steel pipes under internal pressure before and after repair. The work is focused on the development of a numerical model, based on the finite element method, to produce stress concentration factors of plain dents before and after applying glass fiber reinforced epoxy matrix laminate repairs with varying thicknesses. Small-scale steel pipe samples are submitted to denting and the resulting stress concentration in the damaged region is estimated under cyclic internal pressure, before and after repair execution. The finite element model developed is calibrated and validated from correlation between numerical and experimental results. Finally, a parametric study is carried out to evaluate stress concentration factors as a function of the repair thicknesses. These factors can be used in the fatigue assessment of damaged pipes, from the correction of S-N curves.