Free-span occurs normally in a pipeline at uneven seabed, dynamic seabed and pipeline crossing. Free spanning in pipeline causes Vortex Induced Vibration (VIV) fatigue, fracture and bursting. In this paper, a pipeline located in South Pars Gas Field is assessed against local buckling and VIV fatigue using probability of failure theory based on the recommended methodology by Det Norske Veritas (...

A study has been made to discern the mechanisms for the delayed failure of 2-μm thick structural films of n+-type, polycrystalline silicon under high-cycle fatigue loading conditions. Such polycrystalline silicon films are used in smallscale structural applications including microelectromechanical systems (MEMS) and are known to display ‘metal-like’ stress-life (S/N) fatigue behavior in room te...

A typical dynamometer drive shaft was damaged during its working condition. This failure was repeated in four cases. In the present article, a failure analysis of a dynamometer drive shaft has been performed. To analyze the failure, the material investigation was carried out by scanning electron microscopy (SEM) images. Additionally, the micro-structure of the failed coupling shaft was photogra...

This proposed research program will seek to learn the failure mechanisms of multidirectionally woven carbon-carbon composites when subjected to fatigue leading, and characterize this material's potential for use in internal prosthetic devices, e .g . hip and knee implants . Carbon-carbon composites are graphite fiber bundles embedded in a carbon matrix . Currently, implants are made of metals s...

Monotonic and fatigue tests were carried out in four-point bending on a glass fabric/epoxy composite, using two different stress ratios. Ultimate failure both in monotonic tests and in fatigue was precipitated by microbuckling phenomena happening at the compression side of the specimens. The experimental results were evaluated adopting a fatigue model statistically implemented, based on the hyp...

objectives: the purpose of this study was to evaluate the resistance to fatigue failure of five different nickel-titanium rotary files in three different curved trajectories. materials and methods: a total of 150 neoniti a1, race 25.06, mtwo 25.06, twisted file 25.06 and protaper next x2 files with the tip size of 25 were tested (n=30 for each group). three groove types simulating curved canals...

Warm mix asphalts (WMA), because of their low production and compact temperatures, may have different behaviors in long term. In the present work, the energy-based criteria along with the 50% reduction in initial stiffness (Nf50%) using four-point bending test under controlled-strain conditions of 1000 microstrain were applied to compare the prepared two warm mix and HMA samples. All these crit...

PURPOSE To compare the stiffness of locking compression plate (LCP) constructs with or without drilling the near cortex with elongated figure-of-8 holes. METHODS 24 synthetic bones were sawn to create a 10-mm gap and were fixed with a 9-hole 4.5-mm narrow LCP. In 12 bones, the near cortex of the adjacent holes to the LCP holes was drilled to create elongated figure-of-8 holes before screw ins...