Development of non-linear stochastic fatigue crack growth models for structural grade steel

摘要

This paper describes the analysis and quantification of within specimen and between specimen fatigue crack growth variability from tests undertaken on BS 4360: 1990 Grade 50DD (now BS EN 10025: Part 2: 2004, Grade S355K2) steel specimens. A non-linear fatigue crack growth model is presented which draws upon within and between specimen variability, the application of a newly identified and unique intersection point (referred to as the Gurney Point) and the use of reliability updating. This model, which aggregates fatigue crack growth variability over defined increments of growth, provides crisp fatigue life predictions at a sufficiently early stage of fatigue life.