An Application of Fracture Concepts to the Prediction of Critical Length of Fatigue Cracks. Part II. A Review of Pertinent Aspects of Fracture (Theoretical and Analytical Aspects of Fatigue of Metals)

摘要

This part of the report (Volume 2) presents a technical documentary historical review of pertinent theoretical and analytical aspects of fatigue failure and its relationship to fracture mechanics. The review covers the period 1829 to 1970. Fatigue failure, i.e., fracture without gross plastic deformation under repeated application of stress below the proportional limit, has been recognized for at least 138 years. Despite numerous investigations on the subject, there is no available theory for correlating the many variables affecting fatigue failure and for successfully predicting failure. The application of linear elastic fracture mechanics and the thermodynamics of fracture to the crack propagation facet of fatigue is proposed as an approach to the prediction of critical lengths of stable fatigue cracking and unstable fracturing before failure. (Author)