In the present paper research work is presented combining material rel
ated research, weld fabrication related research and research in the f
ield of numerical analysis of welded joint performance. Elements belon
ging to this extensive combination are mechanical testing, fracture me
chanics testing of small scale and full thickness specimens, component
testing including engineering defect assessment and numerical modelli
ng using finite element method. Examples are given for each of the abo
ve mentioned elements.