Fatigue crack growth is a complex process that involves interactions between many elements ranging across several length scales. This work provides an in-depth, experimental study of fatigue crack growth and the relationships between four of these elements: strain field, microstructure, crack path, and crack growth rate. Multiple data sets were acquired for fatigue crack growth in a nickel-base...

OBJECTIVES This research was designed to analyse the frequency spectra of joint crack sounds produced during spinal manipulative therapy applied to the upper cervical spine of 50 volunteers and to determine if the spectra differed between the sexes and or for those with a history of previous neck trauma compared with those without a history of trauma. DESIGN Randomised experimental study. S...

The dislocation shielding field at a crack tip was experimentally proven at the atomic scale by measuring the local strain in front of the crack tip using high-resolution transmission electron microscopy (HRTEM) and geometric phase analysis (GPA). Single crystalline (110) silicon wafers were employed. Cracks were introduced using a Vickers indenter at room temperature. The crack tip region was ...

A B S T R A C T Using a model of a single layered foundation to describe a highway or an airfield pavement and an integral formulation, the problem of a pavement containing on-the-top layer a crack of finite length 2c is solved for the stress distribution around the crack tip. The analysis shows that the stresses possess the usual 1/e 1⁄2 singular behavior which is characteristic of crack probl...

AN EXACT asymptotic analysis is presented of the stress and deformation fields near the tip of a quasistatically advancing plane strain tensile crack in an elastic-ideally plastic solid. In contrast to previous approximate analyses, no assumptions which reduce the yield condition, n priori, to the form of constant inplane principal shear stress near the crack tip are made, and the analysis is v...

A new method for remote crack monitoring, based on the breathing crack phenomenon and wavelet transform, is proposed. During vibration, edges of a crack come into and out of contact which causes non-linear effects in the response of a structure, due to changes in the structural stiffness, as the crack opens and closes. Wavelet Transform is applied to detect such nonlinear effects in the respons...

Infra-red video sequences were taken of directly bonded silicon wafer pairs undergoing the razor blade crack length test for bond strength in a specially designed jig. A series of tests were carried out under controlled atmospheres of nitrogen at various relative humidities. Analysis of the video images showed that the crack continues to propagate rapidly for several minutes after the blade has...

Employing Dynamic Discrete Dislocation Plasticity (D3P), an elastodynamic analysis of the shielding of a stationary crack tip by dislocations is studied. Dislocations are generated via FrankRead sources, and make a negligible contribution to the shielding of the crack tip, whereas dislocations generated at the crack tip via homogeneous nucleation dominate the shielding. Their effect is found to...

Infra-red video sequences were taken of directly bonded silicon wafer pairs undergoing the razor blade crack length test for bond strength in a specially designed jig. A series of tests were carried out under controlled atmospheres of nitrogen at various relative humidities. Analysis of the video images showed that the crack continues to propagate rapidly for several minutes after the blade has...

Image processing technology plays an important part in the analysis and evaluation of pavement surface cracking. The pattern recognition method for crack geometry proposed in this paper makes it possible to extract data necessary for evaluating the extent and severity of cracking quantitatively. In this newly developed method, low-resolution images are used first to extract crack regions, and t...