AN IMPROVEMENT ON PREDICTION OF FATIGUE-CRACK GROWTH FROM LOW-CYCLE FATIGUE PROPERTIES

Theoretical approaches are made in the present study to improve a form er fatigue crack growth (FCG) model based on the conception of the loc al damage accumulation. A new da/dN-Delta K relationship is derived wh ich predicts the stage-II FCG behavior independently from the basic lo w cycle fatigue properties. A satisfactory agreement is found between the predicted and the experimental data of da/dN-Delta K for a quenche d and tempered high-strength steel with different strength levels, and an A533-B1 steel under various load ratios. Some potential physical i mplications of the new da/dN-Delta K relationship are also discussed. (C) 1998 Elsevier Science Ltd. All rights reserved.