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...

The present paper adopts a Bayesian approach to update some of the parameters of the probability distributions governing the reliability assessment of maintained floating structures. It is based on a time dependent fatigue reliability formulation presented earlier but the description of the time to crack initiation, crack growth law and probability of crack detection are updated using the infor...

This paper presents experimental results from the vibration of a polycarbonate beam containing a crack that opens and closes dudng vibration. Several techniques were employed to detect and locate the crack making use of the nonlinearity. “Harmonic mode shapes” proved to be more sensitive to damage than conventional mode shapes. Instantaneous f requency and timefrequency methods also showed clea...

This research was initiated to investigate the capability of using lasers for crack detection in pavements. If such a capability could be developed it would be used to aid in obtaining and evaluating pavement distress and cracking information for the State's P.E.S. procedures, used for maintaining and evaluating pavements. The research effort has involved three stages. The first two stages were...

Abstract. Eddy current testing using a pickup coil is usually applied to the surface detection of cracks because of its high frequency. However, for metal infrastructure, detection of not only the surface but also internal cracks is desired. Therefore, we have developed a low-frequency eddy current testing system to inspect interior structures using a magneto-resistive (MR) sensor with a wide m...

Automated systems for road crack detection are extremely important in road maintenance for vehicle safety and traveler’s comfort. Emerging cracks in roads need to be detected and accordingly repaired as early as possible to avoid further damage thus reducing rehabilitation cost. In this paper, a robust method for Gabor filter parameters optimization for automatic road crack detection is discuss...

One of the useful applications of wireless sensor networks is structural health monitoring, where sensors are distributed to monitor buildings, bridges, large dams, and etc. Out of a large number of application domains we focus on the fatigue crack detection of a structure, e.g., bridge. In this chapter, we summarize the required components for data networking in autonomous fatigue crack detect...

We seek a non-destructive testing method to detect a radial surface breaking crack in a two-dimensional circular disk. The detection method utilizes steady-state electrical boundary measurements. A nonlinear function which characterizes the size and the location of a radial surface crack is constructed based on the knowledge of two data readings of the boundary voltage intensity corresponding t...

15. Supplementary Notes Project performed in cooperation with the Texas Department of Transportation and the Federal Highway Administration. Project Title: Implementation of Automated Pavement Distress Rating Systems 16. Abstract This paper presents the image-processing algorithm customized for high-speed, real-time inspection of pavement cracking. In the algorithm, a pavement image is divided ...