Fatigue life estimation of corroded welded steel joint using probabilistic approach

Abstract

This study presents a probabilistic model to estimate fatigue life of the corroded welded joint using the concept of the limit state function and Monte Carlo procedure. The basis for the assessment is the long-term experiment in a real corrosive environment. Pit-to-crack transition parameters, after three years of corrosion, are estimated using El Haddad model for small cracks. Calibration of the linear elastic fracture mechanics parameters was performed using S-N analysis for the case when the initial crack size is stochastic and for the case when the crack emanates from a corrosion pit. Results of the failure probability calculation for two approaches after the fourth and fifth year of the service life show that the stochastic initial crack size gives higher failure probability and suggests shorter inspection intervals than the ones obtained with deterministic initial crack size.