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Studies of the mechanical properties of elastomeric nanocomposites depending on the shape of the filler particles are carried out. Graphene nanoplates, detonation nanodiamonds, and single-walled graphene nanotubes are used as fillers. Samples are tested for uniaxial tension at a constant speed. The viscoelastic behavior of these composites is studied using a special technique based on the cyclic loading of the sample with increasing strain amplitude at each subsequent step and stops for relaxation after load direction reverse. Experimental tests have shown that the greatest effect of changing the mechanical behavior of the elastomer is observed when graphene nanotubes are used. These composites show well-defined viscoelastic properties and a softening effect, as well as the strongest hardening. It has been hypothesized that all these differences are related to the geometry of the filler and that all these differences are related to filler particle geometry. Graphene nanotubes can be considered as long and flexible fibers that can form a spatial network in the elastomeric matrix even at sufficiently low fillings. When the composite is loaded, this network can be destroyed, and this is accompanied by reorientation and mutual slipping of the nanofibers. These processes require significantly higher energy costs than those for moving and turning granular or lamellar particles. [ABSTRACT FROM AUTHOR]

The paper discusses the enhancement of the energy efficiency of motor vehicles with conventional engines when using a continuously variable mechanical transmission with internal force function control. Such a transmission has torsion shafts working in torsion under conditions of random cyclic loading at a frequency corresponding to the ICE shaft rotation speed. The fatigue strength of torsion shafts can be a limitation on the operating life of the entire transmission. Technological measures increasing the fatigue limit of the torsion shaft material are analyzed. Developing the elastic strains of torsion bars is theoretically considered. The theoretical strain cycle fluctuates with the asymmetry ratio R = 0. The amplitude of the elastic strain is determined by the external load. The test procedure for a prototype vehicle with an engineering specimen of a transmission in specific motor vehicle operating modes is presented. The need for the ongoing monitoring to limit torsional strain by the control system is shown. According to the field test results, the nature of torsion bar loading cycles in operating conditions is estimated in detail. In most operating modes, the experimental character of torsion bar loading has a reversed strain cycle with the negative strain ratio R = −0.04 ... −0.79. The inexpediency of torsion bar hardening is shown. Fragments of oscillograms demonstrating elastic strains of the torsion bars and distribution of the mean and amplitude values of the strain cycles for typical operating conditions are given. [ABSTRACT FROM AUTHOR]

Alloys of the Au-Co system characterized by restricted solubility of the constituents were produced by shear deformation under high quasi-hydrostatic pressure. Resistance to shear strain was recorded during mechanical fusion. The forming pressure dependence of shear stress during deformation has been revealed, with the form of the curve remaining qualitatively unchanged. The form of the curve for the joint deformation of the Au-Co constituents differs from the curve recorded during the deformation of one constituent, namely gold. In the former case there are stages of sharp increase, retardation, and attainment of saturation, whereas in the latter case there is a sharp increase followed by attainment of saturation. This indicates the appearance of the deformation interaction of the constituents, which manifests itself in a prolonged increase in shear stress with an increase in strain, as distinct from the case of a single element, where there occur only structural changes caused by torsion under pressure. After the samples had been made, their Vickers hardness was measured, which demonstrates practically equal values of the hardness of the Au-Co alloys produced under different pressures. [ABSTRACT FROM AUTHOR]

The paper models the mechanical behavior of the human cornea affected by intraocular pressure and external effects. It reviews publications on the development of mathematical models of the cornea and some approaches to studying its mechanical behavior. A finite element model of the cornea is proposed, which allows the stress-strain state in the cornea to be determined from solving the boundary value problem of the theory of elasticity. Test calculations are shown. The model can be used, particularly, for studying the strain of the cornea resulting from surgery. [ABSTRACT FROM AUTHOR]

The plastic properties of commercially pure copper are considered. Using the strain diagrams (for strain rates of 0.002, 0.016, 150.0, 2000.0, and 13300.0 s−1) and the hardening curve for copper under static compression, the analytical dependence of copper yield stress on strain (in the range from 0 to 0.45) and strain rate (in the range from 0.002 to 13300.0 s−1) is found. [ABSTRACT FROM AUTHOR]

The paper studies the effect of mechanical stresses on the value of the coercive force along and across the direction of loading. The applicability of the coercimetric method to the evaluation of tensile stresses in proportion to material yield stress is discussed. Based on the obtained dependences of relative coercive force values, a method for measuring uniaxial tensile stresses without stress relief is proposed. [ABSTRACT FROM AUTHOR]

The effect of crystal orientation and the deformation method (tension and compression) on the deformation behavior of (CoCrFeNi)94Ti2Al4 high-entropy alloy single crystals is studied along two crystallographic orientations ([001] and [111]) at 296 K. It is shown that, at room temperature, the critical resolved shear stresses (τcr) are independent of crystal orientation and the deformation method, and the Schmid law is satisfied. The stress-strain response (σ(ε) curves), strain-hardening coefficient (Θ = dσ/dε) and plasticity are found to depend on crystal orientation and the deformation method (tension and compression). The maximum value of Θ is observed in [001]-oriented crystals upon compression during deformation by slip and twinning, and the maximum tensile plasticity in [001]-oriented crystals is due to the development of a planar structure without twinning. In [111]-oriented crystals (under compression from the onset of plastic deformation), instability in the plastic flow is manifested in the appearance of bands of localized deformation, which are absent under tension in crystals of this orientation. [ABSTRACT FROM AUTHOR]

The problem of elastic wave reflection on the free surface and on the interface with the rigid bidy is investigated in the approximation of geometrical acoustics. In both cases, the interface is considered as a structural element of an inhomogeneous body, which is characterized by dimensions and a set of physical-mechanical parameters. In the continuum mechanics the interface is generally viewed as an infinitely thin layer. Analytical expressions for the Fresnel coefficients allowing us to determine the strain components on the boundary are found at the normal incidence of P and SV waves. The dependences of the Fresnel coefficients and the strain amplitudes as functions of interface thickness and the elastic properties of contacting bodies are calculated and analyzed. [ABSTRACT FROM AUTHOR]

The results of experimental research on residual stresses and plastic deformations by the hardening of the outer and inner surfaces of thin-walled Kh18N10T steel tubes by means of microbeads are described. A phenomenological model for calculating residual stresses and deformation by two-way tube hardening is proposed. A method for parameterization of the mathematical model is presented. The adequacy of the model was verified, and the calculated and experimental data were matched. [ABSTRACT FROM AUTHOR]

A computational model is developed to simulate the stress-strain state in the surface layer of a thin polymer coating during testing for indentation with holding at a constant load under creep conditions. A numerical model is implemented in ANSYS as applied to a coating based on commercial ED-20 epoxy resin with a polyethylenepolyamine hardener. The rheology of the coating material is described by a combined model of an isotropic elastic-viscoplastic medium. In order to identify the model, an experimental indentation diagram obtained from indentation testing under loading conditions similar to those imposed in the simulation is used. Fields of distribution of total equivalent strain and creep strain in the area under the indenter under specified loading conditions are constructed. [ABSTRACT FROM AUTHOR]

In this paper, the authors test a method of studying the stability and stress-strain state of a cylindrical shell structure under various loads in the ANSYS Mechanical APDL 19.2 software package. The analyses are performed using the arc-length method. Shell 181 is chosen as an element type, which makes it possible to account for large strains during the analyses. The shells have fixed-pin joints on two sides and a free edge on the other two sides. A concentrated force and a uniformly distributed load are considered as load cases. Normal displacement vs. load graphs are obtained for all options of the structures considered; the values are calculated with account for geometric nonlinearity. Buckling load values are obtained for various options of structures with a uniformly distributed load, the other structures remain stable. A significant difference in critical values as compared to the linear analysis indicates the need for taking into account geometric nonlinearity. [ABSTRACT FROM AUTHOR]

Three basic and two equivalent stresses complicated by a parameter are considered. The basic equivalent stresses are the maximum normal stress, the von Mises equivalent stress, and the double maximum shear stress. To determine the effect of each basic equivalent stress on the time at the time of failure, their two linear combinations with one material parameter are considered. One of them is a combination of the maximum normal stress and the von Mises equivalent stress (proposed by A. Lebedev, 1965). The other is a combination of the maximum normal stress and the doubled maximum shear stress (proposed by V. V. Nazarov, 2019). The results of lengthy tests of tubular specimens under the action of the axial force and torque are analyzed to determine which variant of the equivalent stress better describes the process of long-term strength, as well as to establish the effect of each basic equivalent stress on the time at the moment of failure in a complex stress state. The unknown parameters are calculated by finding extrema through the solution search menu (Microsoft Office Excel), where the minimum error is taken as the target condition. From the analysis of the errors of the total discrepancy between the experimental data and the approximation in the form of the power dependence between the time at the time of failure and the nominal equivalent stress, it has been found that a linear combination of the maximum normal stress and the doubled maximum shear stress in all the cases considered offers the best approximation of the long-term strength process. From the analysis of the values of material parameters in complicated equivalent stresses, it is not possible to extend the effect of each maximum stress on all the considered series of lengthy tests. [ABSTRACT FROM AUTHOR]

The paper considers an algorithm used for stress-strain state (SSS) determination in an NPP pipeline junction with vessel components. The tensometry results obtained for cylindrical sections of the pipeline, distant from the areas of geometrical discontinuity and stress concentration locations, are used in this case. The temperature fields are taken from solutions of inverse thermoelasticity problems, which allow one to determine the temperature of the coolant and its coefficients of heat transfer to the structure surface. [ABSTRACT FROM AUTHOR]

A model is proposed in which the creep process is delimited in time by two successive stages. To distinguish between these stages, a criterion is proposed (on the diagram of the creep curve, the average angle of inclination of the tangent to the abscissa axis) of the beginning of a change in the shape of a deformable solid (or the appearance of a neck under uniaxial tension). The time moment of the beginning of the change follows from the proposed criterion. As the equation of the mechanical state, the power dependence is taken between the strain rate and stress, according to which an approximation of the experimental creep curve is possible. The verification of the proposed model showed a satisfactory agreement with the experimental creep curves of the VT5 titanium alloy at 650 °C. [ABSTRACT FROM AUTHOR]

The article considers various methods for conical reinforced concrete poles strengthening, which allow increasing of the load-bearing capacity of these structures. Static and dynamic calculations of conical reinforced concrete poles are performed in the SCAD Office 21.1 software package. Based on this calculation, the analysis of the stress state of poles using different methods of structural reinforcement under steady loads of the pole dead load, the tower superstructure weight, the ladder-type gangway weight, and the weight of the equipment, as well as temporary loads (wind, ice), is made. The results of the analysis can be used in the rational choice of methods for strengthening conical reinforced concrete poles. [ABSTRACT FROM AUTHOR]

The problem of elastic waves propagation through the interfaces which are considered as a structure elements of inhomogeneous solid is investigated. An infinitesimal thin layer is the usual model of boundary in the classical mechanics. The considered interfaces are characterized by dimensions and the physical-mechanical properties that are different from ones of the contacting solids. The models of layered and block media are used for these interfaces description. Analytical expressions for the Fresnel coefficients allowing us to find the strain components on the interface are derived. The dependences of Fresnel coefficients and strain amplitudes as functions of interface thickness and elastic properties of the contacting solids are calculated at the normal incidence of P and SV waves on the boundary. Strains features on the interface are analyzed in the frame of two considered models. [ABSTRACT FROM AUTHOR]

In this work, the numerical study of yield phenomenon is addressed. The material for investigation is low-carbon 08PS steel demonstrating the yield phenomenon in simple tensile testing. Judging by the literature review, the number of papers carefully addressing the curves of dependencies of Lüders elongation and band propagation rate on parameters of mathematical model—namely, the amplitude of stress drop and strain hardening factor, is not large. This work aims at filling this gap. [ABSTRACT FROM AUTHOR]

The problem of elastic waves propagation through the contact layer at the boundary conditions of imperfect contact is considered. Boundary conditions modeled by effective spring are used for describing the interface damages determining the imperfect contact of two elastic bodies. According to these boundary conditions the stress is continuous on an interface and the displacement vector is not continuous on the interface. Analytical expressions for the Fresnel coefficients of the contact layer and waves propagating in the layer are derived which allow us to find the intensities for reflected and refracted waves and the strain distribution in the layer. The dependences of reflected wave intensity and strain amplitudes as functions of layer thickness and elastic properties of the contacting solids are calculated and analyzed at the normal incidence wave on the boundary. [ABSTRACT FROM AUTHOR]

This paper numerically investigates the physical behavior of deep geological structures in the Yakutsk-Vilyui large igneous province (LIP). The geophysical data of "Craton-1980" profile was used to create the computer structures of the researched area. To analyze the inelastic deformation, the Nikolaevsky elastoplastic model was used. For investigating the geotectonic processes the strength model, which operates with cohesion and coefficient of internal friction, was adapted to the Nikolaevsky model. The depth analysis of the stress state was realized making use of the pressure and the Lode parameter. It is shown that the distribution of the Lode parameter depends on inelastic strain localization and reveals mainly the shear type of deviatoric stress. The distribution of pressure has a quasi-monotonic increasing with depth, with local disturbances caused by the shear bands in the depth layers of Earth's crust. These features are more pronounced with increasing of horizontal deformation. These results can be used by geologists to evaluate the metamorphism of rocks. [ABSTRACT FROM AUTHOR]

The work represents investigation of cracking the ceramic particle under the plane stress and plane strain deformation of the metal matrix composite at microscale (scale of an individual particle), with the experimentally observed shape of the reinforcing particle being considered. The boundary-value problems are solved numerically by the finite element method using ABAQUS/Explicit software package. The composite material is under both tensile and compressive loads. The influence of residual stresses arising during manufacturing cooling on the stress concentration in the region of the matrix-particle interface and crack initiation and growth is studied under subsequent mechanical loading of the composite material. [ABSTRACT FROM AUTHOR]

A method for modeling thermal destruction of periclase-carbon refractories is proposed. The method is based on the growth of fatigue cracks at elevated temperatures. The stress-strain state of the refractory under the influence of thermal and mechanical factors was determined in dynamics throughout the entire operation cycle. Chemical and abrasive wear of the material were not considered. For calculations, the finite element method was used. Energy criterion was used for calculations of crack growth. The probability of crack growth was determined using the results obtained previously for the stress-strain state of typical defects of refractory materials under the action of a tensile load. Thermal, energy and deformation criteria were formulated that determine the probability of the onset of cracks growth. [ABSTRACT FROM AUTHOR]

Underground mining of coal seams often causes problems associated with the imbalance of the natural coal-methane system. In some cases, during anthropogenic action on the coal seam, an extremely large amount of methane is released, which leads to disasters—methane explosions or emissions of coal and gas, in other cases, very little free methane is released, which greatly complicates the commercial production of coal mine methane. Dynamic impact is one of the tools for managing the conditions of coal seams. As a result of explosive action, extended cracks can form in the coal seam for it degassing. The aim of the work is to consider the type of failure to find ways to optimize the explosive impact on the coal seam. This may contribute to the development of a drilling and blasting passport, depending on the objectives of this impact. To this goal, the work uses a joint model of a gas-saturated coal seam to describe the hierarchical relationship between explosive damage to the coal seam and gas evolution [1]. Based on this model, using the numerical simulation by the smoothed particle hydrodynamics method (SPH) [2, 3], the development of the fracture zone is studied and the stress-strain state of the formation near the face before and after the explosion is determined. The obtained patterns help to predict the reaction of coal to a dynamic effect. This is of great importance for the technology of preliminary degassing of coal seams and for the technology of provoking controlled emissions of coal and gas. [ABSTRACT FROM AUTHOR]

This paper presents the results of numerical simulation of the interaction of a spherical steel projectile with a silicate glass barrier. The initial velocity of interaction is 750 m/s. The problem is solved numerically, by the finite element method, in a three-dimensional formulation within the framework of the phenomenological approach to the mechanics of solids using the author's software package EFES. To describe the processes of deformation, fracture and cracking, the JH-2 model was used, which makes it possible to take into account the large deformations, high strain rates and high pressures that occur in the material. The used calculation algorithm takes into account the formation of discontinuities in the material and the fragmentation of bodies with the formation of new contact and free surfaces. The behavior of the projectile material is described by an elastoplastic medium. The limiting value of the intensity of plastic deformations is taken as a local fracture criterion for the material of the projectile. A detailed numerical analysis of the dynamics of the stress-strain state of a glass barrier and the effect of shock-wave processes on its fracture is carried out. It was found that the main role in the fracture of the barrier, with the considered kinematic and geometric parameters of interaction, is played by wave processes. [ABSTRACT FROM AUTHOR]

The assessment of changes in the stress-strain state of parts and structural elements made of metal materials after a significant period of operation remains an important and urgent task, which is being addressed by specialists in various fields, including non-destructive testing. This paper presents the results of a study of the effect of elastic-plastic deformation by uniaxial tension on the change of the magnetic characteristics of 20K boiler steel, which is used for such critical engineering objects as pressure vessels, including large volumes up to several tens of m3. [ABSTRACT FROM AUTHOR]

The results of a comparative analysis of the stress-strain patterns observed in two- and three-dimensional polycrystalline models under uniaxial tension are presented and discussed. The 3D polycrystalline structure is generated using a step-by-step packing method. Finite-difference calculations of uniaxial tension are carried out for the 3D model and some selected sections located at different depth below the surface. In the latter case, calculations are performed in terms of plane strain and plane stress. Stress and strain fields in 2D and 3D models are compared on the meso- and macroscales. It is found that the 2D approximations impose certain restrictions on the use and interpretation of the results obtained. [ABSTRACT FROM AUTHOR]

This paper presents the results of numerical simulation of the interaction of an elongated glass cylinder with a rigid wall with an initial velocity of 4.2 m/s. The problem is solved numerically, by the finite element method, in a three-dimensional formulation within the framework of the phenomenological approach to the mechanics of a deformable solid using the author's software package EFES. To describe the processes of deformation, fracture and cracking, the JH-2 model was used, which makes it possible to take into account the large deformations, high strain rates and high pressures that occur in the material. The used calculation algorithm takes into account the formation of discontinuities in the material and the fragmentation of bodies with the formation of new free surfaces. A detailed numerical analysis of the dynamics of the stress-strain state of a glass impactor and the effect of shock-wave processes on its fracture is carried out. It was found that the main role in the fracture of the glass impactor, with the considered kinematic and geometric parameters of interaction, are played wave processes. [ABSTRACT FROM AUTHOR]

The paper presents the results of studying the effect of cyclic preload realized by zero-to-tension scheme with different numbers of cycles on the behavior of magnetic characteristics of hot-rolled 08G2B steel followed by elastic uniaxial tension. The cyclic preload affects on the patterns of change of the material's magnetic parameters during subsequent elastic deformation due to the formation of residual compressive stresses generated by preliminary cyclic loading along the tension axis. The ranges of applied tensile stresses have been determined where the magnetic characteristics measured on cyclically pre-deformed specimens with different number of cycles vary uniquely. This principally enables these parameters to be used for the development of nondestructive testing methods for estimating the operational stresses in a 08G2B steel products taking into account the prehistory. [ABSTRACT FROM AUTHOR]

Polycrystalline rhenium is an undeformed metal at room temperature, while in the monocrystalline state rhenium demonstrates considerable plasticity due to the basal slip and the prismatic slip. Such deformation schemes as rolling, bending, shearing, and high-pressure torsion having a different percentage of tensile stress, are considered. Analysis of the dislocation structure of rhenium based on ab initio calculations of its lattice properties is carried out. The type of mechanical behavior of polycrystalline rhenium depends on the share of tensile stress in the deformation scheme. It behaves like a brittle solid under bending, while its behavior is ductile under high-pressure torsion. The cause of its poor plasticity under rolling and bending is the fact that dislocation slip does not activate inside the grains. Possible stress accommodation mechanisms in refractory HCP-metal rhenium at room temperature are discussed. [ABSTRACT FROM AUTHOR]

In this work, plate-form and prism-form samples of the TiNi alloy, which were subjected to low-energy high-current electron-beam treatment (LEHCEB) with a pulse duration τ=2–2.5 µs, energy density ES1=3.8±0.7 J/sm2 and ES2=7±1.4 J/sm2, number of pulses n=32 were studied. The aim of the study was to analyze the stress-strain states in the TiNi alloy surface layers and their evolution when the sample surface orientation changes to the direction of the electron beam. It has been established that under equivalent LEHCEB treatment regimes in the surface layer of the plate- form sample, the residual stresses value is an order of magnitude higher than along the lateral sides of the prism-form sample. This may be due to the mutual compensation of the residual elastic stress fields propagating from opposite irradiated sides of the sample. [ABSTRACT FROM AUTHOR]

In this work, samples of a TiNi-based alloy, which were subjected to a pulsed low-energy high-current electron-beam treatment (LEHCEB) in the melting mode were studied. The aim of the study was to determine the influence of the geometry of electron-beam treatment on the structure and stress-strain states localized in the TiNi alloy surface region. It was found that under equivalent LEHCEB treatment modes, but different orientations of the sample surface with respect to the electron beam, the structural-phase composition and the stress-strain state in the impact area change, and the level of residual stresses in the surface area changes by a 1.5-fold. [ABSTRACT FROM AUTHOR]

The amplitude-frequency characteristics of a water-saturated reservoir under pressure head and non-pressure conditions were estimated for 2017–2018. The measuring wells are located at the territory of the geophysical observatory "Mikhnevo" of IDG RAS. A comparative analysis of the average monthly amplitudes of volumetric strain and groundwater level was performed. Volumetric strain and water level were calculated for period range of 0.5–28 hours in the sliding window of 0.5 hour without overlapping and for periods of semidiurnal and diurnal tidal waves. [ABSTRACT FROM AUTHOR]

This work presents a comparative analysis of inelastic strains in Ti49.1Ni50.9 (at %) alloy samples under isothermal torsional deformation at temperatures of 153 and 293 K. The inelastic deformation behavior of samples with different structural-phase states (B2 or B19′) is investigated. For a correct comparison of the obtained values to the crystallo-graphic resource of inelastic deformation, the experimental torsional strains are converted according to an algorithm based on the concept of equivalent strains for different deformation modes (tension and torsion). [ABSTRACT FROM AUTHOR]

The thermomechanical behavior of a composite material fabricated from high-strength aluminum alloy 6061-T6 reinforced by boron carbide particles is numerically studied. The model microstructure of the composite takes into account the complex shape of particles in an explicit form. Two-dimensional boundary value problems are solved numerically in the plane stress and plane strain formulations using the finite element method. Three types of calculations of the composite deformation are carried out: cooling from the melt to room temperatures, compression from zero initial state and the cooling followed by compression. Sites of the formation of local compressive and tensile stresses in the metal matrix and ceramic particles are found out. Volumetric tensile stresses are detected even under all-round compression realized during cooling. Plastic strain localization and residual stress concentration in the matrix and particle are found to depend on the type of the loading. [ABSTRACT FROM AUTHOR]

Plastic strain localization and stress concentration in aluminum-boron carbide composite subjected to uniaxial compression are studied numerically. 3D and 2D boundary-value problems are solved by the finite element method. Three dimensional irregular shape of a carbide particle is simulated by modified step-by-step procedure. Elastic and elastic-plastic isotropic behavior is assumed for the particle and matrix materials. Comparison of calculation results for 3D, plane strain and plane stress cases is discussed. [ABSTRACT FROM AUTHOR]

Ultrasound therapy looks very promising to treat degenerative changes in the musculoskeletal system and fractures. Computer simulation can help to reveal the acoustic low-energy effects on bone tissue. Usually, the model samples with averaged mechanical characteristics are used to simplify the simulations. However, such assumptions can distort the resulting stress and strain fields, which in turn could lead to an incorrect prediction of the bone tissue regeneration. This paper presents the results of ultrasound exposure of model samples of an elementary form of various compositions with explicit and implicit consideration of the biological tissue structure. The results obtained indicate a gradient distribution of the stress/strain fields with a decrease in the amplitude of the output parameters for model samples with averaged mechanical properties and a two-component composition (cortical and spongy tissue). The interface between the tissues serves as a "secondary" acoustic source as well as a barrier in the case of a two-component "cartilage-cortical tissue" model specimen; the maximum stresses are concentrated there. [ABSTRACT FROM AUTHOR]

In this work, grain-scale simulations of the deformation behavior of an AlSi10Mg alloy produced by selective laser melting are performed. The simulations involve the development of geometrical models of Al-Si eutectic and α-Al dendritic structures with an explicit account of the microstructural features. Finite-element calculations of uniaxial tension of the model microstructures are carried out. The stress and strain fields developing in the Al-Si eutectic and α-Al dendritic structures are analyzed. The stress–strain curves are calculated to obtain a homogenized response of the materials under study. [ABSTRACT FROM AUTHOR]

The article presents the results of calculating the stress-strain state when the C3-C4 segment of the cervical spine with different density of spongy bone tissue of the C3 vertebra is inclined forward. The density of cancellous bone tissue varied from 0.06 to 0.46 g/cm3. The calculation results showed that when a segment is bent, the C3 vertebra with the lowest spongy bone density being considered is more shifted down and forward at the same time while the protrusion of the intervertebral disc in the segment bending direction is the smallest compared to the protrusion of the segment disc with the highest spongy bone tissue density. [ABSTRACT FROM AUTHOR]

This work deals with a viscometer designed to control the viscosity of thixotropic fluids that change their fluidity upon the mechanical stress. [ABSTRACT FROM AUTHOR]

In this paper, the states of stress and strain in the deep structures in the Yakutsk-Vilyui large igneous province (LIP) are numerically analyzed. The "Craton-1980" profile with 60 km depth was chosen because it is characteristic for the Yakutsk-Vilyui LIP and contains deformed crystalline foundation and the upper mantle layer. This geological profile was obtained by deep seismic sounding surveys. Using the "Craton-1980" profile data a 2D computer structural model was constructed. To solve the posed problem, a model of the continental yield stress envelopes (YSE) was used in which the strength properties of Earth's crust layers change in accordance with depth and due to the influence of heat flow from the mantle layer. To describe the inelastic properties, the use of Nikolaevskiy's elastoplastic model was made. Numerical simulation allowed for revealing the regions in the lithosphere responsible for the formation of stress concentrations and inelastic strain localization. The location of these regions was shown to be determined not only by the heterogeneous layers in Earth's crust with curved interfaces but also by pronounced non-monotonic dependence of strength with depth. [ABSTRACT FROM AUTHOR]

The influence of test temperature in the range from –60 to 60°C and strain rate from 1×10–4 to 1×10−2 s−1 on tensile mechanical properties and peculiarities of a plastic flow has been experimentally investigated using the vanadium-alloyed ultrahigh-interstitial austenitic Fe-22Cr-26Mn-1.3V-0.2Ni-0.7C-1.2N (mass %) steel specimens subjected to a 1-hour solid-solution treatment at temperature of 1200°C. It has been established that the decrease in deformation temperature and the increase in strain rate does not change the dominating deformation mechanism of the steel— dislocation slip—but increase a planarity of a dislocation arrangement and promote mechanical twinning as the additional deformation mechanism. The ultrahigh-interstitial steel demonstrates striking temperature and strain rate dependencies of a yield strength in considered loading conditions. [ABSTRACT FROM AUTHOR]