Rethinking fatigue crack growth: Crack growth at constant R and strain energy

Abstract

Abstract This paper is the first of a series attempting to apply my 57‐year experience with durability and damage tolerance of aerospace structures to answer the question; why, after 50 plus years, have we not reached agreement on the validity of current crack growth assumptions. To address this question, new concepts are introduced and interpreted in terms of strain energy. The tentative answer to the question is that when interpreted in terms these new concepts and strain energy, there are serious conceptual errors in the da/dn diagrams that make the data base very difficult to properly interpret. The materials presented raise new questions and provide possible answers to old ones.