Weld defect frequency, size statistics and probabilistic models for ship structures

Ships undergo cyclic loading which combined with weld defects can cause fatigue failure. Remaining fatigue life of structures containing defects can be estimated using the defect size. The defect data for ships is non-existent in literature or belong to old offshore structures. In this research, the data collected from two ships are presented. The statistical analysis of the data shows that the Hybrid Laser Welding has lower defect rates than other common arc welding processes indicating that less quality control inspection may be allowed. The defect length values from the studied ships were smaller than those from offshore structures.