Characters and properties of dislocations in ice are thoroughly reviewed on the basis of the knowledge hitherto obtained by the X-ray topographic method as well as recently found dynamical behavior. Extremely low energy of the faults on the basal plane found by the method leads us to conclude that all of the dislocations in ice should be extended as wide as several tens to one hundred nano-mete...

2014 Constant strain rate compressions along 001 > have been performed on CoO single crystals (03B5 ~ 6 x 10-5 s-1). Yield stresses and work hardening rates have been measured between 77 K and 1 400 K; CoO is very strong when compared to similar compounds. Vickers indentations have been performed on { 100 }, { 110 } and { 111 } faces around the Néel temperature, i.e. between 0 °C and 40 °C...

In simple crystalline materials, plastic deformation mostly takes place by the movement of dislocations. Although the underlying mechanisms in these materials are well explored, in complex metallic alloys--crystalline solids containing up to thousands of atoms per unit cell--the defects and deformation mechanisms remain essentially unknown. Owing to the large lattice parameters of these materia...

Previous work on the elastic deformation of flat-section band clamps has been extended to account for plastic deformation of the band material. Both finite element analysis using a multilinear plastic model and a classical approach using a continuous plastic equation are reported. The excellent agreement between the results of these two approaches provides a high level of confidence in the mode...

Scientific substantiation and practical confirmation of possibility, expediency and efficiency of application of the ultrasonic superficial plastic deformation in zones of welded connections after performance of welding works is given. For this purpose a mathematical model of process of superficial plastic deformation is represent, as the hypercycle of loading consisting of elementary cycles – ...

The processing of bulk metals through the application of severe plastic deformation (SPD) provides an opportunity for achieving excellent grain refinement to the submicrometer or even the nanometer range. These SPD procedures produce materials exhibiting improved mechanical properties including very high strength. This report describes recent results demonstrating the strengthening of conventio...

Boundaries and junctions (both internal and external) can contribute significantly to the plastic deformation of metallic solids, especially when the average size of the grains (phases) is less than hundred nanometres or when the size of the solid itself is of the order of microns. The overall permanent deformation of the solid is a result of a coupling between bulk plasticity with moving inter...

An instrumented indentation method is developed for generating maps of time-dependent viscoelastic and time-independent plastic properties of polymeric materials. The method is based on a pyramidal indentation model consisting of two quadratic viscoelastic Kelvin-like elements and a quadratic plastic element in series. Closed-form solutions for indentation displacement under constant load and c...

Abstract-An Eulerian finite element formulation is presented for problems of large elastic-plastic flow. The method is based on Hill’s variational principle for incremental deformations, and is ideally suited to isotropically hardening Prandtl-Reuss materials. Further, the formulation is given in a manner which allows any conventions finite element program, for “small strain” elastic-plastic an...

Thermo-deformable plastic films experience an optical birefringence phenomenon when they are subjected to mechanical strain, this phenomenon can be described by color fringes behavior observed in sequences of images acquired through photoelasticity assemblies. This paper proposes a temporary morphological analysis that color fringes experience when the plastic film is deformed. For the image an...