TIME-DEPENDENT FATIGUE FRACTURE THEORY AND RESIDUAL LIFE ASSESSMENT TECHNIQUES FOR DEFECTIVE STRUCTURES

Fatigue failure of high temperature structures inpower engineering and petrochemical industry is time dependent. In ordertoestablish the corresponding fracture theory, develop a proper lifeassessment approach and then control the structure failure, many studieswere carried out on this type of failure mechanism in the past years.In the present work, the recent development is reviewed in thefollowing aspects: fracture parameters for crack extension, rules of thecrack growth and residual life estimation, influences of materials aging andenvironment factors, and engineering approaches for structural integrityassessment. Research achievements in this field are summarized and somesuggestions are presented based on the literature.