Fundamental role of local curvature of crystal structure in plastic deformation and fracture of solids

It is shown that strain-induced defects of all kinds are nucleated in local curvature zones of the interfaces between 3D-crystals and 2D-planar subsystem similar to a laser pumping mechanism. Mobile curvature solitons are generalized wave structural carriers of plastic flow. Fracture is the structural phase decay of a crystal in the zones of very high curvature

Search for glitches of gamma-ray pulsars with deep learning

The pulsar glitches are generally assumed to be an apparent manifestation of the superfluid interior of the neutron stars. Most of them were discovered and extensively studied by continuous monitoring in the radio wavelengths. The Fermi-LAT space telescope has made a revolution uncovering a large population of gamma-ray pulsars. In this paper we suggest to employ these observations for the searches of new glitches. We develop the method capable of detecting step-like frequency change associated with glitches in a sparse gamma-ray data. It is based on the calculations of the weighted H-test statistics and glitch identification by a convolutional neural network. The method demonstrates high accuracy on the Monte Carlo set and will be applied for searches of the pulsar glitches in the real gamma-ray data in the future works.Comment: 4 pages, 5 figure

Dynamic recrystallization of Ti-based materials at crack surfaces at elevated temperatures –hybrid cellular automata simulation

In the study a Hybrid discrete-continuum Cellular Automata approach (HCA) based on coupling classical thermomechanics and logics of CA-switching to simulate new phase generation and grain growth is proposed. On the basis of the HCA the numerical experiments on thermal-activated recrystallization of pure titanium in the vicinity of crack edges were conducted. In doing so the 3D cellular automaton simulates the behavior of the V-notched specimen region that imitates the crack tip vicinity. Numerical experiments are aimed at calculating heat expansion in the material under study through taking into account thermal stresses accumulation and microrotation initiation. The latter gives rise to generation of new defects and increasing the local entropy

Influence of ion-beam treatment on structure and defor-mation resistance of 12Cr1MoV steel under static, cyclic and dynamic loading

Features of modification of structure and properties of 12Cr1MoV steel subjected to ion-beam irradiation by zirconium ion beam have been investigated with the use of optical and electron microscopy, and microhardness measurement. It was shown that after the treat-ment the modification occurs across the entire cross-section of specimens with the thickness of 1 mm. Changes in mechanical properties of these specimens under static, cyclic and impact loading were interpreted in terms of identified structure modifications

Molecular dynamics study of cluster structure and properties of rotational waves in solid nanostructures

The paper reports a molecular dynamics analysis of rotary properties of a transformational wave generated due to compressive influence. Studies are performed in the time interval prior to the onset of elastic precursor reflection from the free boundary. It is shown that the leading front of a rotary wave coincides with the transformational wave front. The rotary wave velocity for copper is determined, being equal to 1300 m/s. The values of angular moment projections onto the coordinate axes in a plane perpendicular to wave propagation are found to be symmetrical, and their total sum equals zero

Molecular dynamics study of cluster structure and properties of rotational waves in solid nanostructures

The paper reports a molecular dynamics analysis of rotary properties of a transformational wave generated due to compressive influence. Studies are performed in the time interval prior to the onset of elastic precursor reflection from the free boundary. It is shown that the leading front of a rotary wave coincides with the transformational wave front. The rotary wave velocity for copper is determined, being equal to 1300 m/s. The values of angular moment projections onto the coordinate axes in a plane perpendicular to wave propagation are found to be symmetrical, and their total sum equals zero