Each year, millions of dollars are invested on road maintenance and reparation all over the world. In order to minimize costs, one of the main aspects is the early detection of those flaws. Different types of cracks require different types of repairs; therefore, not only a crack detection is required but a crack type classification. Also, the earlier the crack is detected, the cheaper the repar...

Ultrasonic is one of the most common uses of a non-destructive evaluation method for crack detection and characterization. The effectiveness of the acoustic-ultrasound Structural Health Monitoring (SHM) technique for the determination of the depth of the surface crack was presented. A method for ultrasonic sizing of surface cracks combined with the time domain and frequency spectrum was adopted...

The state of the art in vibration-based damage detection and health and usage monitoring is reviewed. The damage detection concepts and the signal analysis techniques are examined, explained, and compared. Latest advances in signal processing methodologies that are of relevance to vibration based damage detection (e.g., Wavelet Transform and Wigner-Ville distribution) are highlighted. These vib...

The dynamics and diagnostics of cracked rotors have been gaining importance in recent years. The present work deals with the detection of crack in rotor system and determination of crack parameters i.e. position of crack, depth of crack using Artificial Neural Networks (ANN). The detection of crack is based on the continuous wavelet transform (CWT) plots with 1/3 and 1⁄2 critical peaks as the c...

This paper presents a road distress detection system involving the phases needed to properly deal with fully automatic road distress assessment. A vehicle equipped with line scan cameras, laser illumination and acquisition HW-SW is used to storage the digital images that will be further processed to identify road cracks. Pre-processing is firstly carried out to both smooth the texture and enhan...

Post-earthquake structural safety is evaluated manually by certified construction inspectors and structural engineers. They inspect visible damage (e.g. cracks) on critical structural elements (e.g. concrete columns). This process is time-consuming and costly. In order to automate this type of visual inspection, several damage detection methods have been developed. However, most of them can onl...

There are many ways that women support their use of crack cocaine, including sex-for-crack bartering and other forms of prostitution. Empirical studies conducted in the mid-1970s and in the mid-1980s in New York City, and in Chicago in the late 1980s to early 1990s are compared, analyzing similarities and differences between the contemporary crack-prostitution scene and previous prostitution sc...

This paper studies the application of an inverse methodology for problem solving in fracture mechanics using the finite element analysis. The method was applied to both detection of subsurface cracks and the study of propagating cracks. The procedure for detection of subsurface cracks uses a first order optimization analysis coupled with a penalty function to solve for the unknown geometric par...

In this study, we investigated a method for the non-destructive detection of cracks based on an ultrasonic transit timing method. This method is considered to be an effective means for crack monitoring over an extensive coverage area. Aluminum specimens were prepared with a range of crack sizes and subjected to a tone burst wave to investigate the relationship between crack depth and the transi...