Fatigue Life Assessment of Tubular Joints for Jacket Platforms Considering Corrosion

摘要

The effect of corrosion on the fatigue life of tubular joints is studied bynumerical simulation method based on the linear cumulative damagelaw. In this study, the plate thickness wastage and elastic modulusreduction are considered as the dynamic variables during corrosionprocedure. The finite element model (FEM) of a jacket structure isestablished by using the finite element software SESAM and thestructure parameters are adjusted relatively according to the residualwall thickness and elastic modulus. The results show that platethickness wastage has more significant influence on the fatigue life oftubular joints compared with elastic modulus reduction. Meanwhile, therelative variation ratio curves of hot-spot stresses are nonlinear and canbe expressed by the function of time (year). In addition, the tubularjoint may be damaged when the service time is 13 ~ 20 years ifconsidering the influence of plate thickness wastage and elasticmodulus reduction simultaneously.