During the design stage, realistic life time predictions for components help to reduce test cycles and allow for an optimization with respect to both production and repair costs (see e.g. Schuëller et al. 1996). Accurate predictions of the mean life time and its standard deviation can be obtained from a fracture mechanics approach that takes the uncertainties in the material parameters into acc...

ÐGamma-TiAl based alloys have recently received attention for potential elevated temperature applications in gas-turbine engines. However, although expected critical crack sizes for some targeted applications (e.g. gas-turbine engine blades) may be less than 0500 mm, most fatigue-crack growth studies to date have focused on the behavior of large (on the order of a few millimeters) through-thick...

A preliminary study of the effects from age and dehydration on fatigue crack growth in human dentin was conducted. Compact tension (CT) fatigue specimens of coronal dentin were prepared from extracted molars and subjected to high cycle fatigue (10(5)<N<10(6)) under Mode I loading. Young hydrated dentin (mean age=25+/-7 years), old hydrated dentin (mean age=55+/-14 years) and young dehydrated de...

The use of microwave technique has proved to be a viable means for crack detection and sizing surface cracks in metals. In this technique, the surface of the specimen is interrogated with a radiating open-ended waveguide probe and a crack is assumed to be a simple short-circuited rectangular waveguide, causing peturbations in the probe reflection coefficient. Since the growth of fatigue in meta...

Increased traffic speeds and axle loads on modern railways enhance rail track degradation. To eliminate track failure due to rail defects, a condition monitoring system requires methods for the early detection of defects which grow in service. Acoustic emission (AE) monitoring is the only non-destructive technique which might be applied online to study the defect growth under traffic loading. H...

The addition of liquid-filled urea-formaldehyde (UF) microcapsules to an epoxy matrix leads to significant reduction in fatigue crack growth rate and corresponding increase in fatigue life. Mode-I fatigue crack propagation is measured using a tapered doublecantilever beam (TDCB) specimen for a range of microcapsule concentrations and sizes: 0, 5, 10, and 20% by weight and 50, 180, and 460 lm di...

A software tool for automated crack onset and growth simulation based on the eXtended Finite Element Method (X-FEM) is developed. This XFA tool for the first time is able to simulate arbitrary crack growth or composite delamination without remeshing. The automated tool is integrated with Abaqus/Standard and Abaqus/CAE via the customization interfaces. It seamlessly works with the Commercial, Of...

It is well known that the mechanical properties of materials depend of the rolling direction, which means that the direction of specimen cutting affect the obtained values. This feature also exists in the welded joint, where the anisotropy is caused by direction of the deposit welded layers. One high-carbon steel is surface welded by flux-cored wire and specimens were cut in order to determine ...

Article history: Received 5 July 2012 Received in revised form 25 September 2012 Accepted 29 September 2012 The fatigue crack growth of the nickel-based superalloy Haynes 230 was investigated at room temperature and 900 °C using digital image correlation (DIC). As expected, the crack growth rates at high temperature were much faster than at room temperature. However, the crack closure levels, w...

Meshfree methods are viewed as next generation computational techniques. With evident limitations of conventional grid based methods, like FEM, in dealing with problems of fracture mechanics, large deformation, and simulation of manufacturing processes, meshfree methods have gained much attention by researchers. A number of meshfree methods have been proposed till now for analyzing complex prob...