An analysis of inner cone cracks in brittle solids subject to cyclic indentation in liquid is presented. These inner cone cracks, so named because they form well within the maximum contact circle, are postulated to be driven by a hydraulic pumping mechanism. Unlike their more traditional outer cone crack counterparts, inner cones do not appear in monotonic loading or even cyclic loading in the ...

Attached ultrasonic sensors can detect changes caused by crack initiation and growth if the wave path is directed through the area of critical crack formation. Dynamics of cracks opening and closing under load cause nonlinear modulation of received ultrasonic signals, enabling small cracks to be detected by stationary sensors. A methodology is presented based upon the behavior of ultrasonic sig...

The dynamic behaviour of a structure changes when it is subject to damage such as cracking. Recently research has been directed at employing conventional Modal Analysis techniques to investigate this change in simple structures and to study the dependency on the location and size of a crack. The use of the modeshapes to characterise the dynamic behaviour of the structure would require several a...

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...

Understanding of crack growth behaviour is necessary to predict accurate fatigue lives. Out-of-phase thermomechanical propagation tests were performed on FB2 steel used in high-temperature steam turbine sections. Testing results showed closure where the compressive part cycle affected rate. Crack closing stress was observed be different, and had more influence rate, than opening stress. rate la...

In this article, an implementation of the so-called "novelty detection" method to monitor damage in structures is proposed. Whereas conventional damage identiication procedures have the limitation of requiring a suuciently precise mathematical model of the structure , the novelty detection approach requires no "a priori" model, making the method more applicable to systems of arbitrary complexit...

We characterize wave propagation along an infinitely long crack or conduit in an elastic solid containing a compressible, viscous fluid. Fluid flow is described by quasi-onedimensional mass and momentum balance equations with a barotropic equation of state, and the wall shear stress is written as a general function of width-averaged velocity, density, and conduit width. Our analysis focuses on ...