Grain refinement improves the mechanical properties and formability of metals and alloys. So far, several different grain refinement methods have been proposed and studied. Severe plastic deformation is one of the most promising and efficient methods. Therefore, in the present study the possibility of imposing a two-step severe plastic deformation (Extrusion and Equal channel angular pressing) ...

The solutions to classical problems of perfectly bonded and sliding circular inhomogeneities in a remotely loaded infinite matrix are constructed by using an appealing choice of dimensionless material parameters that represent the in-plane average normal stress and the maximum shear stress at the center of the inhomogeneity, scaled by the corresponding measures of remote stress. The ovalization...

The existence of Eshelby’s equivalent inclusion solution is proved for a degenerate “transformed” ellipsoidal inhomogeneity in an infinite anisotropic linear elastic matrix. We prove the invertibility of the fourth rank tensor expression, C S + C(I − SE), where C is the stiffness tensor of the matrix, C ′ is the stiffness tensor of the inhomogeneity, SE is the Eshelby tensor, and I is the symme...

Traumatic aortic rupture (TAR) is one of the most significant causes of motor-vehicle fatalities with the majority of injuries occurring in the peri-isthmus region. Despite the fact that TAR accounts for 20% of the total automobile fatalities, there is uncertainty regarding its etiology and underlying mechanisms. Finite element (FE) models are essential for calculating the strains and stresses ...

We determined inhomogeneity of strains around discontinuities as well as changes in orientation of collagen fibrils under applied load in skin. Second Harmonic Generation (SHG) images of collagen fibrils were obtained at different strain magnitudes. Changes in collagen orientation were analyzed using Fast Fourier Transforms (FFT) while strain inhomogeneity was determined at different distances ...

The topological derivative of cost functionals J that depend on the stress (through the displacement gradient, assuming a linearly elastic material behavior) is considered in a quite general 3D setting where both the background and the inhomogeneity may have arbitrary anisotropic elastic properties. The topological derivative DJ(z) of J quantifies the asymptotic behavior of J under the nucleati...

High-pressure torsion (HPT) imparts inhomogeneous strain to process discs with low in the center and higher at outer edge. Microscopy microhardness indentation have been used characterize correlate this inhomogeneity strain, but similar exploration other properties has uncommon. In work, electrical conductivity of pure copper processed by HPT was characterized respect equivalent cutting them in...

Based on the Frobenius series method, stresses analysis of the functionally graded rotating thick cylindrical pressure vessels (FGRTCPV) are examined. The vessel is considered in both plane stress and plane strain conditions. All of the cylindrical shell properties except the Poisson ratio are considered exponential function along the radial direction. The governing Navier equation for this pro...

Single compression tests were conducted for two types of pure Al (99.99%): one processed using equal-channel angular pressing (ECAP) through route Bc for 8 passes and the other with the same ECAP but successively annealed at 573K for 1 h. The distributions of the equivalent strain introduced by the compression were quantitatively examined by finite element analysis (FEA). Comparison was made be...

This work investigated the electrical properties in AlGaN/GaN/Si HEMTsgrown by molecular beam epitaxy. The behavior have been using electric permittivity, modulus formalism and conductance measurements. As has found from conductance, dispersive is related to barrier inhomogeneity deep trap layer. On other hand, strain relaxation of charge transport studied both permittivity formalisms.