Projeto de aparato de fadiga em risers rígidos com dano mecânico

Abstract

This study aims to evaluates experimentally the fatigue of steel rigid risers that are subjected to plain dents due to mechanical damage, assessment of their associated stress concentration factors under uniform internal pressure and cyclic bending loads. The work was focused on the design and manufacturing of a test apparatus which provides all necessary requirements for experimental simulation using a vibratory table, capable of reproducing cyclic movements to small-scale samples of rigid risers, and a data acquisition system to evaluate strains and stresses on the damaged section. Additionally, a numerical model, based on the finite element method, still under development, is used to evaluate strain levels and stress concentration factors on the damaged region under internal pressure and alternating bending moment imposed to sample. The finite element model is indeed calibrated form correlation between numerical and experimental results in order to evaluate stress concentration factors of dented pipes under combined alternating bending and cyclic internal pressure. Finally, comments and considerations are presented in view of the obtained results herein and further works.