Parallel tubular channel angular pressing (PTCAP) process is a novel recently developed severe plastic deformation technique for fabrication of ultrafine grained (UFG) metallic tubes. This new process consists of two half cycles and is affected by several parameters such as channel angles, deformation ratio and curvature angles. In this paper, the effects of these parameters on the plastic defo...

Since tubes have numerous industrial applications, different attempts are focused on the Severe Plastic Deformation (SPD) processes of tubes. As an illustration, Tube Channel Pressing (TCP) is an attractive process for this purpose since it can be used for processing of different sizes of tubes. However, more attempts are needed to improve the outcomes of TCP. For example, imposing of greater s...

The potential energy landscape of a flowing metallic glass is revealed using the activation-relaxation technique. For a two-dimensional Lennard-Jones system initially deformed into a steady-state condition through quasistatic shear, the distribution of activation energies is shown to contain a large fraction of low-energy barriers, consistent with a highly nonequilibrium flow state. The distrib...

For application of the plastic analysis and design methods the control of the plastic behaviour of the structures is an important requirement. In this study, the complementary strain energy of the residual forces is considered as an overall measure of the plastic performance of the structure. Shakedown theorem for the analysis of the plastic behaviour of the laterally loaded piles is developed ...

An analytical method for predicting elastic–plastic stress distribution in a cylindrical pressure vessel has been presented. The vessel material was a ceramic/metal functionally graded material, i.e. a particle–reinforcement composite. It was assumed that the material’s plastic deformation follows an isotropic strain-hardening rule based on the von-Mises yield criterion, and that the vessel was...

In hot forming process, the workpiece undergoes plastic deformation at high temperature and the microstructure of the workpiece changes according to the plastic deformation. These changes affect the mechanical properties of workpiece. In order to optimize this process, both the plastic deformation of workpiece and its microstructural changes should be taken into consideration. Since material be...

in this paper, the correlation between the surface rumpling and cracking phenomena with twinning mechanism during plastic deformation of hadfield steel has been investigated. the effect of stacking fault energy and the amount of strain are evaluated. the experimental samples with specific amounts of carbon, manganese and aluminum resulting in different stacking fault energies, were produced usi...

A COMMON APPROACH used in formulating elastoplastic constitutive equations is to partition the total strain rate into its elastic and plastic parts, and then develop the constitutive expression for the plastic strain rate using the concept of the yield surFace in stress space. An alternative approach is to partition the stress rate into its elastic and plastic parts, and then develop the consti...

A study is made into the effect of the critical current density dependence upon the value of plastic strain on the critical state stability in hard and composite superconductors under conditions of plastic yield of the material. There have been found criteria of the critical state stability relative to the jointly developing magnetic flux jumps and plastic strain jerks.

Hysteresis loop curves are highly important for numerical simulations of materials deformation under cyclic loadings. The models mainly take account of only the tensile half of the stabilized cycle in hysteresis loop for identification of the constants which don’t vary with accumulation of plastic strain and strain range of the hysteresis loop. This approach may be quite erroneous particularly ...