... understood, and must be studied using spectrum fatigue tests carried out to very long lives. To quantify the effect of spectrum load control errors on the rate of fatigue damage accumulation for a standard servo-hydraulic fatigue test machine, a damage ratio parameter for crack initiation is calculated using...

... analyses were used to observe fatigue crack initiation. Persistent slip markings have been identified. In parallel, a three-dimensional finite element model of crystalline plasticity, named Cristal-ECP, has been developed in both ABAQUS ™ and CAST3M ™ finite element codes. The numerical studies performed...

... 1 105 cycles, which was about 1/1000 of L10. The report suggests that the crack initiates at an extremely early stage of the life period, as the butter y s wings are accompanied by cracks around the non-metallic inclusions 4 . Nélias et al. 5 investigated the behavior of crack initiation...

... setup is minimal. KEYWORDS: Fatigue damage, fatigue crack, crack initiation, thermography Introduction Within repeatedly loaded steel structures, geometric notches, stiffness changes, or weld seams constitute the critical details for potential fatigue damage. In particular, weld seams pose signi cant...

... initiates at the inner surface; some of these propagate further through the wall thickness. The number of cycles to crack initiation is estimated from surface replicas taken during intermittent stops, whereas the crack depth of fatigue cracks is measured using an ultrasound time of flight diffraction...

...F Mueller; A Scholz; C Berger High temperature components with notches, defects, and flaws can introduce crack initiation and crack propagation under service conditions. Fracture mechanics procedures are needed to study crack problems and to support an advanced remnant life evaluation. Since a more...

...GK Shek; J Cui; V Perovic CANDU Zr-2.5Nb pressure tubes are susceptible to a crack initiation mechanism known as Delayed Hydride Cracking (DHC), which is a process that involves hydrogen diffusion, hydride precipitation, hydride region formation, and fracture at a flaw tip. An overload occurs when...

...K Wasmer; KM Nikbin; GA Webster In this paper, creep crack initiation and growth data are reported on type 316L(N) stainless steel at 650°C on compact tension (CT) specimens and on plates containing a semi-elliptical surface defect. The compact tension tests were carried out according to standard...

...N Gérard; R Leroy; O Girard; N Ranganathan In a previous study, we showed that crack initiation life at a notch tip can be modeled as the micro crack propagation life from an initial microstructural defect up to a crack size of about 500 µm. This model is based upon the assumption that short cracks...