We view the emergence of disorientation boundaries in crystals and the formation of micropores as complementary mechanisms of relaxation of internal strain during severe plastic deformations of polycrystals. Using an assumption of self-similarity of the grain refinement process, we obtain kinetic equations for two scalar parameters characterizing the structure of the material: the total area of...

The paper deals with the elastic-plastic wave propagations in an anisotropic material subjected to impact loading with emphasis on an ideal fibre-reinforced cubic material under two-dimensional plane strain condition. The system of partial differential equations is hyperbolic. Therefore a characteristic-based difference method is proposed to calculate the formation of the plastic zone at the cr...

Using mechanics models of contacting surfaces under both normal and tangential loads, a mechanistic framework has been developed for assessing material resistance to initiation of abrasive damage. Solutions are presented for the critical loads to initiate yielding and cracking at blunt contacts, as well as those to attain a prescribed plastic penetration depth and cause cracking from within the...

The elastic coupling between plastic events is generally invoked to interpret plastic properties and the failure of amorphous soft glassy materials. We report an experiment where the emergence of a self-organized plastic flow is observed well before the failure. For this we impose an homogeneous stress on a granular material, and measure local deformations for very small strain increments using...

The official material used in table tennis balls was changed from celluloid to plastic, a material free of celluloid, in 2014. The purpose of this study was to understand the differences and similarities in the two types of ball materials by comparing their behavior upon collision with a table. The behavior of the balls before and after collision with a table, at various initial speeds ranging ...

A plastic crystal, solid electrolyte was prepared by mixing tetrabutylammonium hexafluorophosphate salt, (C4H9)4-NPF6, (10 molar %) with succinonitrile, SCN, (N≡C−CH2−CH2−C≡N), [SCN-10%TBA-PF6]. The resultant waxy material shows a plastic crystalline phase that extends from −36°C up to its melting at 23°C. It shows a high ionic conductivity reaching 4×10-5 S/cm in the plastic crystal phase (15°...

Abstract—A model to predict the plastic zone size for material under plane stress condition has been developed and verified experimentally. The developed model is a function of crack size, crack angle and material property (dislocation density). Simulation and validation results show that the model developed show good agreement with experimental results. Samples of low carbon steel (0.035%C) wi...

Chalk is the constituent material of numerous oil reservoirs in North Sea. The mechanical behaviour of a saturated chalk has been largely studied. However, different aspects of its behaviour are not yet well understood: material characteristics depend on the saturating fluids and chalk response is timedependent. This paper proposes the PASACHALK numerical model: an elasto-plastic constitutive l...

It is proposed that by using computing analysis software and 3D fabrication techniques, low cost plastic trumpet bells could be produced for different music genres by altering their timbres. These may be attached to the trumpet in a similar manner to that of a tuning bell trumpet. The novel bells are designed to eliminate or enhance particular harmonics to change their brightness by altering th...

Steady state crack propagation produce substantial plastic strain gradients near the tip, which are accompanied by a high density of geometrically necessary dislocations and additional local strain hardening. Here, the objective is to study these gradient effects on Mode I toughness of a homogeneous rate-sensitive metal, using a higher order plasticity theory. Throughout, emphasis is on the tou...