Studies on the effect of weld defect on the fatigue behavior of welded structures

Structural integrity isstated as the science and technology of margin between safety and disaster.Systematic prediction of structural integrity of critical structures such ascombustion chambers,pressure vessels,nuclear reactor components,boilers etc.,ensures the human safety,environmental protection,and the economical considerations.The present work aims at prediction of fatigue behaviour of symmetric structures like pressure vessels in the presence of common welding defects such as lack of fusion (LOF),lack of penetration (LOP) and porosity.A ring type specimen which replicates the stress pattern in thepressure vessel is considered for the study of severity of weld imperfections.Initial dimensions of weld defects are arrived by performing NDT inspection.Crack growth analysis is carried out to determine the remaining life of the welded joint with defects.