Optimising the shielded metal arc welded cruciform joint dimensions of ASTM 517 F grade steels containing LOP defects

A new method was developed to optimise the dimensions of shielded metal arc welded (SMAW) cruciform joints, containing lack of penetration (LOP) defects, to attain maximum fatigue lives. High strength, quenched and tempered steel (ASTM 517 F grade) was used as the base material throughout the investigation. Design of experiments (DoE) concept was used to optimise the required number of experiments. Fatigue experiments were conducted in a mechanical resonance pulsator, under constant amplitude loading. The optimisation procedure was incorporated by (i) response table and response graph, (ii) normal probability plot, and (iii) analysis of variance (ANOVA) techniques.