With the expanding demand on application of magnesium alloys in automotive and aerospace industries, robust methods in fatigue characterization of commercially available magnesium alloys with high specific strength is anticipated. In this paper, rotating bending load controlled tests has been studied on specimens machined from an extrusion piece of AZ31B. Due to asymmetric and anisotropic behav...

OBJECTIVE Cognitive behavior therapy (CBT) leads to a significant reduction in fatigue severity and impairment in patients with chronic fatigue syndrome (CFS). The purpose of the present study was to determine whether the effect of CBT for CFS on fatigue and impairment is mediated by a decrease in avoidance behavior and focusing on fatigue. METHODS For this purpose, we reanalyzed a randomized...

671 Sleep-Wake Behavior in CFS—Rahman et al about the mechanisms responsible for the experience of poor quality sleep in CFS. Human sleep is part of an oscillating sleep-wake pattern following a circadian rhythm.8 These cyclical rhythms are directed by the brain’s biological “clock” located in the suprachiasmatic nucleus and cause fluctuation of body temperature, hormone levels, and sleep over ...

The initiation and growth behavior of short fatigue cracks from the interfacial micro-notches in a SCS-6/Ti composite at various maximum applied stress levels were quantitatively characterized. Micro-notches in the interfacial reaction layer were induced by applying monotonic tensile loading prior to fatigue testing. The propagation and arrest behaviors of each individual crack were carefully m...

In this study, the pitting type of corrosion growth characteristics, fatigue crack initiation and propagation behavior; axial fatigue tests were carried out on precipitation hardened martensitic Custom 450 steel in the air and 3.5wt% NaCl solution. Using the ratio of the depth to the half-width of the pits; (a/c)= 1.5±0.2 the corrosion pit depth growth law was obtained as a function of stress a...

Rapid advances are taking place to develop hydrogels of high stretchability and toughness, but fatigue fracture has not been studied for any hydrogels. This negligence hinders the development of hydrogels and their applications. Herewe initiate a study of fatigue fracture of hydrogels.We choose polyacrylamide hydrogel as a model material. To place fatigue fracture in context, we apply monotonic...

The fatigue behavior of a nickel-base superalloy was investigated under total strain-controlled mode at high temperature. The fatigue life, cyclic stress response behavior and hysteresis loop of the superalloy were investigated under isothermal low cycle fatigue (LCF) conditions. The superalloy exhibited cyclic hardening and softening behaviors during the process of fatigue loading. The hystere...