This manuscript presents an integrated approach for automatic crack monitoring combining photogrammetry and image processing. In summary, the strain field obtained from photogrammetric data is used to map the cracked areas where image processing is applied. All processing is completely automatic since only a threshold value, related to the width of the crack, needs to be provided. Direct Shear ...

Avoidance of cracking damage due to hydration is an important objective in the design of nuclear reactor containments. Assessment of the safety against cracking requires a realistic material model and its effective numerical implementation. Toward this goal, the paper develops a comprehensive material model which includes approximate simulation of cracking based on the principles of cohesive fr...

We develop a model for the propagation of a fluid-filled crack in a porous medium. The problem is motivated by the mechanism whereby drainage networks may form in partially molten rock below the Earth‘s lithosphere. Other applications include the propagation of hydraulic fractures in jointed rocks and in oil drilling operations, and the formation of dessication cracks in soils. Motivated by the...

Civil infrastructure can suffer from concrete cracks due to the creep, shrinkage, diverse natural loading, aging, and corrosion of reinforcement. Concrete cracks are one of the important features when analyzing the current condition of concrete structures. The shape, length, and width information on concrete cracks are possible to conduct an initial maintenance for the structure safety. General...

Fluctuations in the crack tip structure should result in the release of elastic waves that propagate both into the bulk as well as along the surface. Ramanathan and Fisher (1997), and Morrisey and Rice (1998) examined such wave interactions in a series of increasingly sophisticated models. The possibility that in-plane and out-of-plane perturbations could persist along the crack surface, result...

In this paper an analytical crack propagation scenario is proposed which assumes that a crack propagates in the tooth root in both the crack depth direction and the tooth width direction, and which is more reasonable and realistic for non-uniform load distribution cases than the other presented scenarios. An analytical approach is used for quantifying the loss of time-varying gear mesh stiffnes...

In this paper, the conformal mapping method was adopted to solve the problem of an infinite plate containing a central lip-shaped crack subjected to remote biaxial loading. A kind of leaf-shaped configuration was also constructed in order to solve the problem. The analytical result showed that the singularity order of the stress field at the tip of a lip-shaped crack remains −1/2, despite the d...

Precracked and notched specimens were used to investigate the fracture mechanism of a bainite steel at low temperature. The critical fracture event was studied using metallographic sectioning method. The results showed that the critical cleavage event was different in the precracked and the notched specimens. At -196C, all specimens fractured at lower-shelf region without any ductile crack grow...