(FBRs). The factors influencing fatigue lifetime in sodium compared with that in air were investigated by observation of surface cracks in 316FR steel. Furthermore, the effects of sodium environment on fatigue were investigated based on examining the results of thermal striping tests, etc., obtained up to now. The results of the fatigue tests show that many micro cracks in the shearing directio...

An evolutionary approach for fatigue crack detection in cantilever type of machine structure is investigated in this paper. Fault like fatigue crack detection has received a great attention in recent years. A surface transverse open edge crack is considered for this study. Actual fatigue crack may behave like a non-linear due to opening and closing under vibration. But due to small level of vib...

The characterization of critical levels of microstructural damage that can lead to fatigue-crack propagation under high-cycle fatigue loading conditions is a major concern for the aircraft industry with respect to the structural integrity of turbine engine components. The extremely high cyclic frequencies characteristic of in-flight loading spectra necessitate that a damage-tolerant design appr...

Using cold working fastener holes is a simple life enhancement procedure that strengthens metallic components by retarding crack growth around a hole. In the present paper, the residual stress field that is induced by the hole expansion process is obtained based on different material models namely elastic perfect plastic, isotropic hardening and kinematic hardening using three-dimensional finit...

Reliable and quantitative non-destructive evaluation for small fatigue cracks, in particular those in hard-to-inspect locations, is a challenging problem. Guided waves are advantageous for structural health monitoring due to their slow geometrical decay of amplitude with propagating distance, which is ideal for rapid wide-area inspection. This paper presents a 3D laser vibrometry experimental a...

*Correspondence: Alex Hansen, Department of Physics, Norwegian University of Science and Technology (NTNU), Høyskoleringen 5, NO-7491 Trondheim, Norway e-mail: [email protected] We investigate numerically the dynamics of crack propagation along a weak plane using a model consisting of fibers connecting a soft and a hard clamp. This bottom-up model has previously been shown to contain the comp...

Step-loading fatigue tests have been conducted on two � -TiAl alloys with differing microstructures following quasi-static indentations intended to simulate assembly-related impact damage to lowpressure turbine blades. Fatigue tests were conducted at 600 �C using computer-controlled servohydrau­ lic loading at a frequency of 20 Hz. Reasonably good agreement was achieved between the fatigue data...

Fatigue crack initiation and early short crack propagation behaviour in two microstructural variants of a recently developed Low Solvus, High Refractory (LSHR) disc superalloy at room temperature has been investigated by three-point bending with replication procedure. The results shows that fine gained (FG) LSHR possesses higher fatigue life due to its better crack initiation resistance, limite...

In 2004, a team comprised of researchers and service providers launched the Safer Crack Use, Outreach, Research and Education (SCORE) project in the Downtown Eastside of Vancouver, British Columbia, Canada. The project was aimed at developing a better understanding of the harms associated with crack cocaine smoking and determining the feasibility of introducing specific harm reduction strategie...