To model elastic wave scattering from fatigue cracks in metals, studies were conducted of wave scattering from artificial cracks using ultrasonic spectroscopy. The cracks are of two dimensional planar strips oriented at various angles and embedded in diffusion bonded titanium alloy. The crack is assumed to behave as a Griffith crack and expressions (derived by Achenbach1) to describe diffracted...

Crack detection is very important to prevent major accident in civil engineering works, but it is still problematic in implementation. The traditional K-means algorithm only takes pixel values into account, which causes the extraction of pavement crack is not accurate. In order to improve the efficiency and accuracy, a novel algorithm is proposed. It is a combination of the improved K-means alg...

Pavement crack is the main form of early diseases of pavement. The use of digital photography to record pavement images and subsequent crack detection and classification has undergone continuous improvements over the past decade. Digital image processing has been applied to detect the pavement crack for its advantages of large amount of information and auto detection. The application of digital...

Crack detection in structures is an important and time-consuming element of monitoring the health ensuring structural safety. The traditional visual inspection can be unsafe may produce inconsistent results. Thus, there a need for method to easily accurately identify analyze cracks. In this study, algorithms automatically detecting size location cracks concrete images were developed. Cracks det...

The present paper is concerned with the effective numerical implementation of the two-dimensional dual boundary element method, for linear elastic crack problems. The dual equations of the method are the displacement and the traction boundary integral equations. When the displacement equation is applied on one of the crack surfaces and the traction equation on the other, general mixed-mode crac...

In this paper a new method of microwave nondestructive testing based on electromagnetic guided waves is applied to detect circumferential crack in the piping system of nuclear power plants. Microwaves as continues wave are generated by a network analyzer and amplitude of the reflection coefficient is measured by this network. For detection of any type of crack with any orientation in the pipe, ...

We show that for the simulation of crack propagation in quasi-brittle, two-dimensional solids, very good results can be obtained with an embedded strong discontinuity quadrilateral finite element has incompatible modes. Even more importantly, we demonstrate these without using a tracking algorithm. Therefore, patterns several cracks, including branching, becomes possible. The avoidance algorith...

The detection, location, and sizing of a fatigue crack emanating from a fastener hole in an aluminum plate is investigated. Two linear arrays of surface mounted piezoelectric disk transducers send and receive ultrasonic guided waves that are transmitted, reflected, and scattered by both the joint geometry and the fatigue crack. A tomography algorithm is used to detect and locate the crack. Ampl...

Lasers provide a non-contact and remote inspection method with high resolution and sensitivity. As a crack detection tool, laser ultrasonics can be used to image surface-breaking cracks with microscopic precision. By monitoring the local elastic scattering conditions and dynamic motion fields present in the immediate vicinity of a surface-breaking crack site, the local crack morphology can be m...

This paper presents crack detection in concrete structure based on fuzzy logic. Safety inspection of concrete structures is very important since it is closely related with the structural health and reliability. Automated structural health monitoring system becomes necessity in recent years that encourages various researches to be going on in this area. Cheap availability of digital cameras make...