Analysis of fatigue in the weld of the joints in the fixed offshore platforms.

Abstract

Four tubular joints of a fixed offshore platform are modelled using finite elements to evaluate respective fatigue lives and comparison with the results obtained from conventional models in frame elements. Stress concentration factors (SCF’s) calculated from parametric formulas are also compared with those obtained from finite elements models. The results of this work have the intention of verifying the validity of the refinement of fatigue analysis on critical joints of platforms and the evaluation of its consequences in the inspection plan. Results show that finite elements analysis is recommended for joints whose type and/or behaviour is not consistent with standard models, used by computational programs. From four analised joints, two of them would not need to be part of inspection plan.