In this paper we apply the method developed by Rice [1], of solving for the elastic field of a crack with a front perturbed from some reference shape, to solve the elasticity problems of somewhat circular planar tensile cracks under arbitrary load distributions. The method is based on a known solution for the stress intensity factor along a circular crack due to a pair of wedge-opening point fo...

The permeability of the preform composite materials used in liquid molding processes such as resin transfer molding and structural reaction injection molding is a complex function of weave pattern and packing characteristics. The development of tools for predicting permeability as a function of these parameters is of great industrial importance. Such capability would speed process design and op...

To study the three-dimensional size, shape, and motion of the mitral leaflets and annulus, we surgically attached radiopaque markers to sites on the mitral annulus and leaflets in seven sheep. After 8 days of recovery, the animals were sedated, and three-dimensional marker positions were measured by computer analysis of biplane videofluorograms (60/s). We found that the oval mitral annulus beca...

A method has been developed in which cineradiography is used for the assessment of the opening angle of implanted Bjork-Shiley prosthetic valves. The method is based on the fact that the ring and the disc, which are known to be circular, appear to be elliptical on x-ray films. The spatial position of the valve can be retrieved from the characteristics of these ellipses when vectoranalysis is ap...

This article is devoted to evaluating the effectiveness of I-beams with different web perforations: hexagonal, round, oval and elliptical. The technology manufacturing castellated beams described. For purpose verification analytical calculation beam hexagonal perforation for comparison by finite element method given. To correctly assess stress-strain state, mesh elements in area openings was co...

Study of permeability of Fibrous Composites is important in several natural and industrial processes in mechanical engineering. In this study, a comprehensive mathematical model is presented for calculation of normal permeability of ordered elliptical fibrous media. An innovative scale-analysis technique is employed for determining the normal permeability of elliptical fibrous media. In this te...

An isogeometric boundary element method (IGABEM) is developed for the analysis of two-dimensional linear and isotropic elastic bodies governed by couple stress theory. This theory simplest generalized continuum that can effectively model size effects in solids. The fundamental solutions are explicitly derived used to construct integral equations. A new equation arises obtain moments rotations i...

The propagation rate of a fatigue crack in nodular cast iron, loaded cyclic tension, has been studied situ by X-ray computed tomography and digital volume correlation. semi-elliptical initiated from an asymmetric corner notch evolved to semi-circular shape, initially with higher growth towards one edge the before along front became essentially independent position. phase congruency displacement...

different languages are classified in different types according to different elliptical positions in coordinate sentences. in the following, i shall briefly outline this typology and then show the status of persian in this hierarchy. moreover, i will demonstrate that two functional factors; ease of processing and temporal order, are in competition to specify the elliptical positions in these se...

In his 1985 article (“Projection pursuit”), Huber demonstrates the interest of his method to estimate a density from a data set in a simple given case. He considers the factorization of density through a Gaussian component and some residual density. Huber’s work is based on maximizing Kullback–Leibler divergence. Our proposal leads to a new algorithm. Furthermore, we will also consider the case...