The resonance phenomenon observed in Rayleigh wave scattering from surface-breaking cracks has been investigated using Freund's results on reflection of Rayleigh waves from an infinite crack edge. To model the crack as a section of acoustic waveguide, resonances are treated as standing waves in the length and depth directions. The model takes both faces of the crack into consideration, and this...

In this paper, the evaluation of the characteristics of a new type rotating eddy-current probe for nondestructive Eddy-Current Testing (ECT) is carried out using 3-D edge-based FEM. The changes of the induced electromotive force are monitored for various inner and outer types of thin cracks inside the metal plate. It was veri ed that although the intensity of the signal obtained by this new typ...

Abstract-Continuing a recent investigation of interface cracks, attention is paid to the exterior crack. Two elastic solids bonded over a finite segment of their boundary and capable of transmitting shear and tensile tractions are considered. It is found that one of the edge cracks remains completely closed under shear alone, and opens gradually as the level of tension is increased. Both crack ...

We present an image filter that transforms an input line drawing into an image of a fractured surface, where the cracks echo the input drawing. The basis of our algorithm is the Voronoi diagram of a weighted graph, where the distance between nodes is path cost in the graph. Modifying the edge costs gives us control over the placement of region boundaries; we interpret region boundaries as crack...

A methodology for the detection and removal of cracks on digitized paintings. The objective of this research is to develop an automatic crack detection system. The algorithm is composed of two parts; image processing and image classification. In the first step, cracks are distinguished from background image easily using the filtering, the improved subtraction method, and the morphological opera...

in the traditional hole drilling method the in-plane stresses are studied in detail and the interlaminar stresses are not taken seriously. the interlaminar stresses on the free edge of composite materials are important and can cause matrix cracking and delamination. inserting holes in composite laminates causes free edges and it can induce interlaminar shear and normal stresses. in this researc...

Shielding interaction effects of two parallel edge cracks in finite thickness plates subjected to remote tension load is analyzed using a developed finite element analysis program. In the present study, the crack interaction limit is evaluated based on the fitness of service (FFS) code, and focus is given to the weak crack interaction region as the crack interval exceeds the length of cracks (b...

We theoretically investigate the Fermi-edge singularity in a spin-incoherent Luttinger liquid. Both cases of finite and infinite core hole mass are explored, as well as the effect of a static external magnetic field of arbitrary strength. For a finite mass core hole the absorption edge behaves as (omega-omega th)alpha/square root of absolute value (ln(omega-omega th)) for frequencies omega just...