ABSTRACT
A predicative model for fatigue degradation process is of decisive help for inspection planning (Lassen and Recho, 2009). Two distinctive models are S-N model and Fracture Mechanics (FM) model. S-N model calculates fatigue damage based on Palmgren-Miner’ rule together with S-N curves, while FM model predicts damage evolution in terms of crack propagation. Most of studies on inspection planning are based on FM model
1 INTRODUCTION
Structural integrity is a common issue of concern in many engineering fields and industries, e.g. ships, offshore platforms, nuclear pressure structures, wind turbines, bridge decks, etc. The Integrity of ship structures can be compromised by fatigue cracks, corrosion and other mechanical incentives. Among them, fatigue cracks can be more critical than others, as it can result in catastrophic rupture. Generally, fatigue cracks are cause by local stress concentrations in connections and holes. Welded joints are the concerns of this paper, as they are the most common connections in modern steel structures, and are prone to fatigue cracks due to material inhomogeneities, welding flaws, and complicated local geometries (Fricke, 2003).
