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...

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, ...

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...

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...

A method for the detection of cracks in old paper photographs is presented. Cracks in photographic prints usually result from a folding of the paper support of the photograph; they often extend across the entire image, along a preferred orientation. A first clue we exploit for crack detection is the fact that old prints have a characteristic sepia hue, due to aging and to the type of processing...

This paper proposes a method to reduce noise and extract crack indications from detection signals of a 48-channel ECT system based on its signal phase characteristics. Because this 48-channel ECT system performs two kinds of scanning patterns: U-scan and T-scan, and obtains two sets of signal distributions for one scanning area simultaneously, the proposed method uses a two-stage process that i...

Visual inspection by a human operator has been mostly used up till now to detect cracks in sewer pipes. In this paper, we address the problem of automated detection of such cracks. We propose a model which detects crack fractures that may occur in weak areas of a network of pipes. The model also predicts the level of dangerousness of the detected cracks among five crack levels. We evaluate our ...