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...

Self-healing polymers composed of microencapsulated healing agents exhibit remarkable mechanical performance and regenerative ability, but are limited to autonomic repair of a single damage event in a given location. Self-healing is triggered by crack-induced rupture of the embedded capsules; thus, once a localized region is depleted of healing agent, further repair is precluded. Re-mendable po...

The stress intensity factor solution for embedded circular cracks, semicircular and part-circular surface cracks in plates, quartercircular corner cracks in rods, and semicircular surface cracks at a hole in a plate are evaluated using a finite element alternating method. This method of superposition employs the standard 20-noded solid element solution for the untracked solid, and the complete ...

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 ...

In the last decades the field of structural health monitoring and damage detection has been intensively explored. Active vibration technique allows to excite the structure at high frequency vibrations which are sensitive to small damage. Ideal candidates for the generation of high frequency (ultrasonic) signals are piezoelectric PZT transducers, due to their small size, low cost and large bandw...

This paper presents a novel real-time crack identification method to determine the position and depth of a transverse open crack on a rotating shaft. A newly developed wireless sensor capable of being mounted directly on the shaft can be employed to monitor acceleration at different points of a shaft in a rotating coordinate system. The vibration parameters obtained from a Finite Element Model ...

Cantilever beam is a simplified sample of a lot of mechanical components used in a wide range of applications, including many industries such as gas turbine blade. Due to the nature of the operating conditions, beams are subject to variety of damages especially crack propagates. Crack propagation may lead to catastrophic failure during operation. Therefore, online detection of crack presence an...

This paper presents a novel real-time crack identification method to determine the position and depth of a transverse open crack on a rotating shaft. A newly developed wireless sensor capable of being mounted directly on the shaft is employed to monitor acceleration at different points of the shaft in a rotating coordinate system. The vibration parameters obtained from the wireless sensors and ...

Rotating shafts are important and responsible components of many machines, such as power generation plants, aircraft engines, machine tool spindles, etc. A transverse shaft crack can occur due to cyclic loading, creep, stress corrosion, and other mechanisms to which rotating machines are subjected. If not detected early, the developing shaft crack can lead to a serious machine damage resulting ...