Following the 2010 Maule and 2011 Tohoku earthquakes, many studies have examined the relation between megathrust earthquakes and subsequent deformation. Here, we apply simple models based on mode II shear cracks, including approximated effects of the free surface to study induced deformation during coseismic and early postseismic stages. We distinguish between buried and surface ruptures repres...

A selection of surface crack problems is presented to provide insights into Stage I and early Stage II fatigue crack growth. Edge cracks at 45o and 90o to the surface are considered for cracks growing in single crystals. Both single crystal slip and conventional plasticity are employed as constitutive models. Edge cracks at 45o to the surface are considered that either (i) kink in the direction...

It is well known that the near-tip displacement eld on a crack surface can be represented in a power series in the variable p r, where r is the distance to the tip. It is shown herein that the coe cients of the linear terms on the two sides of the crack are equal. Equivalently, the linear term in the crack opening displacement vanishes. The proof is a completely general argument, valid for an a...

In this paper we examine the conditions for surface topography evolution and crack growth/fracture during the cyclic actuation of polysilicon microelectromechanical systems (MEMS) structures. The surface topography evolution that occurs during cyclic fatigue is shown to be stressassisted and may be predicted by linear perturbation analyses. The conditions for crack growth (due to pre-existing o...

The high-cycle, push-pull fatigue fracture behavior of high-C, Si-Al-rich nanostructured bainitic steel was studied through the measurement of fatigue limits, a morphology examination and phase composition analysis of the fatigue fracture surface, as well as fractography of the fatigue crack propagation. The results demonstrated that the push-pull fatigue limits at 10⁷ cycles were estimated as ...

Solutions of stress intensity factors for external and internal unpressurized and pressurized surface cracks in internally pressurized thick-walled reactor pressure vessels are determined directly by a three-dimensional displacement-hybrid finite element method. The finite element method is based on a rigorous modified variational principle of the total potential energy, with arbitrary element ...

This paper investigates the role of material properties on crack path selection in adhesively bonded joints. First, a parametric study of directionally unstable crack propagation in adhesively bonded double cantilever beam specimens (DCB) is presented. The alternating crack trajectories in specimens of various material systems are simulated using the finite element method and the results indica...

The life of a structure can be extended by early detection of cracks with appropriate repairs. In reality, structural failure is always accompanied by the formation of cracks and early detection of cracks is essential in extending structure life and preventing structural failure(1). Therefore, there is a huge amount of research on monitoring surface crack development in concrete structures, esp...

The theory for the constant rate of crack closure was investigated. The aim of this theory is to explain why the rate of crack closure is constant during the wetting stage of healing. Assuming that a surface crack in a material is treated by compression or with solvent, its crack closes up at a constant rate and its shape is independent of time. This approach was based on the Gibbs energy of an...

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...