Fatigue life prediction of shielded metal are welded cruciform joints containing LOP defects by a mathematical model

A new mathematical model is developed to predict the fatigue life of Shield ed Metal Are Welded (SMAW) cruciform joints containing Lack of Penetration (LOP) defect. High strength, quenched and tempered steel (ASTM 517 'F' Grad e) is used as the base material throughout the investigation. Four factors, five level, central composite, rotatable design matrix is used to optimise the required number of experiments. Fatigue experiments have been conducte d in a mechanical resonance pulsator, under constant amplitude loading. The model is developed by Response Surface Method (RSM). Analysis of Variance (ANOVA) technique is applied to check the validity of the model. Student's t-test is utilised to find out the significant factors. The effect of joint dimensions on fatigue life have been analysed in detail. (C) 1999 Elsevier Science Ltd. All rights reserved.