Effect of thermal treatment on the fatigue crack propagation behavior of a new Ni-base superalloy Xingbo Liu a,*, ling Xu a, Ever Barbero a, Wei-Di Cao b, Richard L. Kennedy b a West Virginia University, Morgantown, WV 26506-6106, USA b Allvac, an AT! Technologies Company, Monroe, NC 28111-5030, USA Received 22 October 2006; received in revised form 23 March 2007; accepted 10 May 2007 The effec...

The elements of the concrete structure are most frequently affected by cracking. Crack detection is essential to ensure safety and performance during its service life. Cracks do not have a regular shape, in order to achieve the exact dimensions of the crack; the general mathematical formulae are by no means applicable. The authors have proposed a new method which aims to measure the crack dimen...

By partitioning the total stresses in a damaged composite into either mechanical and residual stresses or into initial and perturbation stresses, it was possible to derive several exact results for the energy release rate due to crack growth. These general results automatically include the effects of residual stresses, traction-loaded cracks, and imperfect interfaces. The exact energy release r...

By partitioning the total stresses in a damaged composite into either mechanical and residual stresses or into initial and perturbation stresses, it was possible to derive several exact results for the energy release rate due to crack growth. These general results automatically include the effects of residual stresses, traction-loaded cracks, and imperfect interfaces. The exact energy release r...

Pulsed infrared laser irradiation was used to positively identify small fatigue cracks on the surface of fatigue damaged Ti–6Al–4V specimens. The resulting transient thermoelastic deformation perceptibly changes the opening of partially closed surface cracks without affecting other scatterers, such as surface grooves, corrosion pits, coarse grains, etc. that might hide the fatigue crack from ul...

BACKGROUND The role of peers (former or current drug users) in reducing risky behavior within methamphetamine and crack smokers has not been well described or researched. The current study not only explores the role of peers in reducing risk factors for morbidity within the illicit drug smoking population in the Downtown Eastside (DTES) community of Vancouver but it also investigates the change...

This is the second in a series of two papers generated from a study on probabilistic meshless analysis of cracks. In this paper, a stochastic meshless method is presented for probabilistic fracture-mechanics analysis of linear-elastic cracked structures. The method involves an element-free Galerkin method for calculating fracture response characteristics; statistical models of uncertainties in ...

X-ray absorption microtomography, a high resolution variant of medical “CT”, quantifies threedimensional microstructures efficiently and noninvasively. With this imaging modality, determination of the three-dimensional spatial distribution of crack opening as a function of applied load has helped clarify important physical processes of roughness-induced fatigue crack closure. There is a real ne...

Fatigue and stress crack detection in metallic structures is of utmost importance to the in-service inspections of metallic components. Beside the crack detection, the prediction of the crack size leads to a better estimation of the useful life of the metal in service. Currently, there are several prominent nondestructive testing (NDT) techniques for detecting and sizing surface cracks in metal...