Fatigue resistance of nanocrystalline commercial pure titanium obtained by hydrostatic extrusion was investigated. Coarse grained titanium and Ti6Al4V alloy were used as the reference materials. The fatigue limit and fatigue life examined at constant stress amplitude, were found to increase significantly compared to those of the coarse-grained counterparts. It is suggested that the observed imp...

Reservoir parks are the main place of storage petroleum products. There has been a tendency transition to use larger tanks in recent years, which is economically justified. However, it leads fire risk increase accumulate large quantities Tank one most dangerous emergency event, can lead not only significant material damage but also ecological human losses case spreading other tanks. To ensure s...

A general condition of nucleation in elastoplastic materials is derived and specified for dilatational phase transitions (PT). The work integral in the nucleation criterion is calculated numerically after solution of a set of boundary-value problems using finite elements method. The example of the relation between applied axial stress, volumetric transformation strain and PT temperature is dete...

Time-dependent creep stress redistribution analysis of thick-walled FGM spheres subjected to an internal pressure and a uniform temperature field is investigated. The material creep and mechanical properties through the radial graded direction are assumed to obey the simple power-law variation throughout the thickness. Total strains are assumed to be the sum of elastic, thermal and creep strain...

Micropipette aspiration (MPA) is a widely applied method for studying cortical tension and deformability. Based on simple hydrostatic principles, this assay allows the application of a specific magnitude of mechanical stress on cells. This powerful method has revealed insights about cell mechanics and mechanosensing, not only in Dictyostelium discoideum but also in other cell types. In this cha...

Non-associative elasto-plasticity is the working model of plasticity for soil and rock mechanics. Yet, it is usually viewed as non-variational. In this work, we prove a contrario the existence of a variational evolution for such a model under a natural capping assumption on the hydrostatic stresses and a less natural mollification of the stress admissibility constraint. The obtained elasto-plas...

In this article, we estimate hydrostatic stress developed in gallium ion implanted gallium nitride epitaxial layers using Raman measurements. We have calculated deformation potential constants for E2(high) mode in these epi-layers. The presence of a polar phonon-plasmon coupling in these systems has also been demonstrated. In as-implanted samples, with an increase in implantation fluence, we ha...

A hybrid finite element scheme, based on assumed deviatoric fluid stresses in the element and continuous velocity fields at the element-boundaries, is presented. The deviatoric stress and hydrostatic pressure field are subject a priori to the constraints of balance of momenta. the advantages of the present scheme are discussed, and its versatility is demonstrated through a few numerical example...

The hydrostatic extrusion is a new method of extrusion process. The most important advantage of this method is reduction of friction and close tolerance for the coating thickness. In this study, the hydrostatic extrusion simulation of bimetallic wires has performed using of finite element method. In the following the advantages of hydrostatic extrusion compared to the direct extrusion are prese...

Laboratory experiments and field observations suggest that the degeneration of basin-scale internal standing waves into packets of solitary waves is an important mechanism for the transfer of energy within the internal wavefield in lakes. Since these shorter solitary waves break at the boundaries, this process provides a flux path from the wind to the turbulent benthic boundary layer. However, ...